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Filed Pursuant to Rule 497
Registration Statement No. 333-187447

PROSPECTUS SUPPLEMENT

(To prospectus dated June 6, 2014)

$100,000,000

6.25% Notes due 2024

We are an internally-managed, non-diversified closed-end management investment company that has elected to be regulated as a business development company under the Investment Company Act of 1940, as amended. Our investment objective is to maximize our portfolio total return by generating current income from our debt investments and capital appreciation from our equity-related investments.

We are offering $100,000,000 in aggregate principal amount of 6.25% notes due 2024, or the “Notes.” The Notes will mature on July 30, 2024. We will pay interest on the Notes on January 30, April 30, July 30 and October 30 of each year, beginning on July 30, 2014. We may redeem the Notes in whole or in part at any time or from time to time on or after July 30, 2017, at the redemption price set forth under “Specific Terms of the Notes and the Offering—Optional redemption” in this prospectus supplement. The Notes will be issued in minimum denominations of $25 and integral multiples of $25 in excess thereof.

The Notes will be our direct unsecured obligations and rank pari passu, or equally in right of payment, with all outstanding and future unsecured unsubordinated indebtedness issued by Hercules Technology Growth Capital, Inc.

We intend to list the Notes on the New York Stock Exchange, or NYSE, and we expect trading in the Notes on the NYSE to begin within 30 days of the original issue date under the symbol “HTGX.” The Notes are expected to trade “flat,” which means that purchasers will not pay, and sellers will not receive, any accrued and unpaid interest on the Notes that is not reflected in the trading price. Currently, there is no public market for the Notes.

An investment in the Notes involves risks that are described in the “Supplementary Risk Factors” section beginning on page S-16 in this prospectus supplement and the “Risk Factors” section beginning on page 11 of the accompanying prospectus.

This prospectus supplement and the accompanying prospectus contain important information you should know before investing in the Notes. Please read this prospectus supplement and the accompanying prospectus before investing and keep it for future reference. We file annual, quarterly and current reports, proxy statements and other information about us with the Securities and Exchange Commission. This information is available free of charge by contacting us at 400 Hamilton Avenue, Suite 310, Palo Alto, California 94301, or by telephone by calling collect at (650) 289-3060 or on our website at www.htgc.com. The information on the websites referred to herein is not incorporated by reference into this prospectus supplement or the accompanying prospectus. The SEC also maintains a website at www.sec.gov that contains information about us.

The underwriters may also purchase up to an additional $4,600,000 total aggregate principal amount of Notes offered hereby, to cover overallotments, if any, within 30 days of the date of this prospectus supplement. If the underwriters exercise this option in full, the total public offering price will be $104,600,000, the total sales load (underwriting discounts and commissions) paid by us will be $3,138,000, and total proceeds, before expenses will be $101,462,000.

THE NOTES ARE NOT DEPOSITS OR OTHER OBLIGATIONS OF A BANK AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE CORPORATION OR ANY OTHER GOVERNMENT AGENCY.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Delivery of the Notes in book-entry form only through The Depository Trust Company will be made on or about July 14, 2014.

Joint Book-Running Managers

Co-Managers

The date of this prospectus supplement is July 9, 2014.

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You should rely only on the information contained in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information contained in this prospectus supplement and the accompanying prospectus is accurate only as of the date on the front cover of this prospectus supplement or such prospectus, as applicable. Our business, financial condition, results of operations and prospects may have changed since that date.

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Prospectus Supplement

Prospectus

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S-2

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S-5

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S-8

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S-12

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SUPPLEMENTARY RISK FACTORS

Investing in our securities involves a number of significant risks. Before you invest in our securities, you should be aware of various risks, including those described below and those set forth in the accompanying prospectus. You should carefully consider these risk factors, together with all of the other information included in this prospectus supplement and the accompanying prospectus, before you decide whether to make an investment in our securities. The risks set out below and in the accompanying prospectus are not the only risks we face. Additional risks and uncertainties not presently known to us or not presently deemed material by us may also impair our operations and performance. If any of the following events occur, our business, financial condition, results of operations and cash flows could be materially and adversely affected which could materially adversely affect our ability to repay principal and interest on the Notes. In addition, the market price of the Notes and our net asset value could decline, and you may lose all or part of your investment. The risk factors described below, together with those set forth in the accompanying prospectus, are the principal risk factors associated with an investment in our securities, including the Notes, as well as those factors generally associated with an investment company with investment objectives, investment policies, capital structure or trading markets similar to ours.

The Notes will be unsecured and therefore will be effectively subordinated to any secured indebtedness we have currently incurred or may incur in the future.

The Notes will not be secured by any of our assets or any of the assets of our subsidiaries. As a result, the Notes are effectively subordinated to any secured indebtedness we or our subsidiaries have currently incurred and may incur in the future (or any indebtedness that is initially unsecured to which we subsequently grant security) to the extent of the value of the assets securing such indebtedness. In any liquidation, dissolution, bankruptcy or other similar proceeding, the holders of any of our existing or future secured indebtedness and the secured indebtedness of our subsidiaries may assert rights against the assets pledged to secure that indebtedness in order to receive full payment of their indebtedness before the assets may be used to pay other creditors, including the holders of the Notes. As of March 31, 2014, we had no borrowings outstanding under our Union Bank Facility, which is secured by debt investments in our portfolio companies and related assets or our Wells Facility, which is secured by loans in the borrowing base for the Wells Facility.

The Notes will be structurally subordinated to the indebtedness and other liabilities of our subsidiaries.

The Notes are obligations exclusively of Hercules Technology Growth Capital, Inc. and not of any of our subsidiaries. None of our subsidiaries is a guarantor of the Notes and the Notes are not required to be guaranteed by any subsidiaries we may acquire or create in the future. A significant portion of the indebtedness required to be consolidated on our balance sheet is held through our SBIC subsidiaries. For example, at March 31, 2014, we have issued $190.2 million in SBA-guaranteed debentures in our SBIC subsidiaries. The assets of such subsidiaries are not directly available to satisfy the claims of our creditors, including holders of the Notes. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Financial Condition, Liquidity and Capital Resources” in the accompanying prospectus for more detail on the SBA-guaranteed debentures.

Except to the extent we are a creditor with recognized claims against our subsidiaries, all claims of creditors (including trade creditors) and holders of preferred stock, if any, of our subsidiaries will have priority over our equity interests in such subsidiaries (and therefore the claims of our creditors, including holders of the Notes) with respect to the assets of such subsidiaries. Even if we are recognized as a creditor of one or more of our subsidiaries, our claims would still be effectively subordinated to any security interests in the assets of any such subsidiary and to any indebtedness or other liabilities of any such subsidiary senior to our claims. Consequently, the Notes will be structurally subordinated to all indebtedness and other liabilities (including trade payables) of any of our subsidiaries and any subsidiaries that we may in the future acquire or establish as financing vehicles or otherwise. As of March 31, 2014, we had no borrowings outstanding under either our Wells Facility or our Union

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Bank Facility and approximately $190.2 million of indebtedness outstanding incurred by our SBIC subsidiaries, HT II and HT III. All of such indebtedness would be structurally senior to the Notes. In addition, our subsidiaries may incur substantial additional indebtedness in the future, all of which would be structurally senior to the Notes.

The indenture under which the Notes will be issued will contain limited protection for holders of the Notes.

The indenture under which the Notes will be issued offers limited protection to holders of the Notes. The terms of the indenture and the Notes do not restrict our or any of our subsidiaries’ ability to engage in, or otherwise be a party to, a variety of corporate transactions, circumstances or events that could have an adverse impact on your investment in the Notes. In particular, the terms of the indenture and the Notes will not place any restrictions on our or our subsidiaries’ ability to:

In addition, the indenture will not require us to offer to purchase the Notes in connection with a change of control or any other event.

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Furthermore, the terms of the indenture and the Notes do not protect holders of the Notes in the event that we experience changes (including significant adverse changes) in our financial condition, results of operations or credit ratings, as they do not require that we or our subsidiaries adhere to any financial tests or ratios or specified levels of net worth, revenues, income, cash flow, or liquidity.

Our ability to recapitalize, incur additional debt and take a number of other actions that are not limited by the terms of the Notes may have important consequences for you as a holder of the Notes, including making it more difficult for us to satisfy our obligations with respect to the Notes or negatively affecting the trading value of the Notes.

Certain of our current debt instruments include more protections for their holders than the indenture and the Notes. See “Risk Factors—In addition to regulatory requirements that restrict our ability to raise capital, our Credit Facilities, the Convertible Senior Notes and the 2019 Notes contain various covenants which, if not complied with, could accelerate repayment under the facility or require us to repurchase the Convertible Senior Notes and the 2019 Notes thereby materially and adversely affecting our liquidity, financial condition, results of operations and ability to pay dividends” in the accompanying prospectus. In addition, other debt we issue or incur in the future could contain more protections for its holders than the indenture and the Notes, including additional covenants and events of default. The issuance or incurrence of any such debt with incremental protections could affect the market for and trading levels and prices of the Notes.

An active trading market for the Notes may not develop or be maintained, which could limit the market price of the Notes or your ability to sell them.

The Notes are a new issue of debt securities for which there currently is no trading market. We intend to list the Notes on the NYSE within 30 days of the original issue date. Although we expect the Notes to be listed on the NYSE, we cannot provide any assurances that an active trading market will develop for the Notes or that you will be able to sell your Notes. If the Notes are traded after their initial issuance, they may trade at a discount from their initial offering price depending on prevailing interest rates, the market for similar securities, our credit ratings, general economic conditions, our financial condition, performance and prospects and other factors. The underwriters have advised us that they intend to make a market in the Notes, but they are not obligated to do so. The underwriters may discontinue any market-making in the Notes at any time at their sole discretion. Accordingly, we cannot assure you that a liquid trading market will develop for the Notes, that you will be able to sell your Notes at a particular time or that the price you receive when you sell will be favorable. To the extent an active trading market does not develop, the liquidity and trading price for the Notes may be harmed. Accordingly, you may be required to bear the financial risk of an investment in the Notes for an indefinite period of time.

If we Default on our obligations to pay our other indebtedness, we may not be able to make payments on the Notes.

Any default under the agreements governing our indebtedness, including a default under the Wells Facility, the Union Bank Facility, the Convertible Senior Notes, the 2019 Notes, and the Asset-Backed Notes or other indebtedness to which we may be a party that is not waived by the required lenders or holders, and the remedies sought by the holders of such indebtedness could make us unable to pay principal, premium, if any, and interest on the Notes and substantially decrease the market value of the Notes. If we are unable to generate sufficient cash flow and are otherwise unable to obtain funds necessary to meet required payments of principal, premium, if any, and interest on our indebtedness, or if we otherwise fail to comply with the various covenants, including financial and operating covenants, in the instruments governing our indebtedness, we could be in default under the terms of the agreements governing such indebtedness. In the event of such default, the holders of such indebtedness could elect to declare all the funds borrowed thereunder to be due and payable, together with accrued and unpaid interest, the lenders under the Wells Facility and the Union Bank Facility or other debt we may incur in the future could elect to terminate their commitments, cease making further loans and institute foreclosure proceedings

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against our assets, and we could be forced into bankruptcy or liquidation. If our operating performance declines, we may in the future need to seek to obtain waivers from the required lenders under the Wells Facility or Union Bank Facility or the required holders of our Convertible Senior Notes, 2019 Notes, Asset-Backed Notes or other debt that we may incur in the future to avoid being in default. If we breach our covenants under the Wells Facility, Union Bank Facility, the Convertible Senior Notes, the 2019 Notes or other debt and seek a waiver, we may not be able to obtain a waiver from the required lenders or holders. If this occurs, we would be in default under the Wells Facility or Union Bank Facility, the Convertible Senior Notes, the 2019 Notes, the Asset-Backed Notes or other debt, the lenders or holders could exercise their rights as described above, and we could be forced into bankruptcy or liquidation. If we are unable to repay debt, lenders having secured obligations, including the lenders under the Wells Facility and the Union Bank Facility, could proceed against the collateral securing the debt. Because the Wells Facility, the Union Bank Facility and the Convertible Senior Notes have, and any future credit facilities will likely have, customary cross-default provisions, if the indebtedness under the Notes, the Wells Facility, Union Bank Facility, the Convertible Senior Notes, the 2019 Notes, or the Asset-Backed Notes or under any future credit facility is accelerated, we may be unable to repay or finance the amounts due. See “Description of the Notes.”

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USE OF PROCEEDS

We estimate that the net proceeds we will receive from the sale of the $100.0 million aggregate principal amount of Notes in this offering will be approximately $96.5 million (or approximately $101.4 million if the underwriters fully exercise their overallotment option) after deducting the underwriting discount of approximately $3.0 million (or approximately $3.2 million if the underwriters fully exercise their overallotment option) payable by us and estimated offering expenses of approximately $500,000 payable by us.

We expect to use the net proceeds from this offering to fund investments in debt and equity securities in accordance with our investment objective and for other general corporate purposes. We may also use the net proceeds from this offering to fund the conversion of any of our Convertible Senior Notes which holders may elect to convert.

We intend to seek to invest the net proceeds received in this offering as promptly as practicable after receipt thereof consistent with our investment objective. We anticipate that substantially all of the net proceeds from any offering of our securities will be used as described above within three to six months, depending on market conditions. We anticipate that the remainder will be used for working capital and general corporate purposes, including potential payments or distributions to shareholders. Pending such use, we will invest a portion of the net proceeds of this offering in short-term investments, such as cash and cash equivalents, which we expect will earn yields substantially lower than the interest income that we anticipate receiving in respect of investments in accordance with our investment objective.

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RATIO OF EARNINGS TO FIXED CHARGES

For the three month period ended March 31, 2014 and for the years ended December 31, 2013, 2012, 2011, 2010 and 2009, our ratio of earnings to fixed charges, computed as set forth below, were as follows:

For purposes of computing the ratios of earnings to fixed charges, earnings represent net increase in stockholders’ equity resulting from operations plus fixed charges. Fixed charges include interest and credit facility fees expense and amortization of debt issuance costs.

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CAPITALIZATION

The following table sets forth (i) our actual capitalization as of March 31, 2014, and (ii) our capitalization as adjusted to give effect to the sale of $100.0 million aggregate principal amount of Notes in this offering (assuming no exercise of the overallotment option) after deducting the underwriting discounts and commissions of approximately $3.0 million payable by us and estimated offering expenses of approximately $500,000 payable by us. You should read this table together with the “Use of Proceeds” section and our statement of assets and liabilities included elsewhere in this prospectus supplement.

(1)  Does not include the 650,000 shares of our common stock issued under our ATM Program.

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UNDERWRITING

We are offering the Notes described in this prospectus supplement and the accompanying prospectus through a number of underwriters. Keefe, Bruyette & Woods, Inc., Jefferies LLC and RBC Capital Markets, LLC are acting as representatives of the underwriters. We have entered into an underwriting agreement with the underwriters. Subject to the terms and conditions of the underwriting agreement, we have agreed to sell to the underwriters, and each underwriter has severally and not jointly agreed to purchase from us, the aggregate principal amount of Notes listed next to its name in the following table:

Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the Notes sold under the underwriting agreement if any of these Notes are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the nondefaulting underwriters may be increased or the underwriting agreement may be terminated.

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the Notes, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, and other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officer’s certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Commissions and Discounts

An underwriting discount of 3.0% per Note will be paid by us. This underwriting discount will also apply to any Notes purchased pursuant to the overallotment option.

The following table shows the total underwriting discounts and commissions that we are to pay to the underwriters in connection with this offering. The information assumes either no exercise or full exercise by the underwriters of their overallotment option.

The underwriters propose to offer some of the Notes to the public at the public offering price set forth on the cover page of this prospectus supplement and some of the Notes to certain other Financial Industry Regulatory Authority (FINRA) members at the public offering price less a concession not in excess of 2.00% of the aggregate principal amount of the Notes. The underwriters may allow, and the dealers may reallow, a discount not in excess of 1.20% of the aggregate principal amount of the Notes. After the initial offering of the Notes to

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the public, the public offering price and such concessions may be changed. No such change shall change the amount of proceeds to be received by us as set forth on the cover page of this prospectus supplement.

The expenses of the offering, not including the underwriting discount, are estimated at $500,000 and are payable by us.

Overallotment Option

We have granted an option to the underwriters to purchase up to an additional $4,600,000 aggregate principal amount of the Notes offered hereby at the public offering price within 30 days from the date of this prospectus supplement solely to cover any overallotments. If the underwriters exercise this option, each will be obligated, subject to conditions contained in the underwriting agreement, to purchase a number of additional Notes proportionate to that underwriter’s initial principal amount reflected in the above table.

No Sales of Similar Securities

We have agreed not to directly or indirectly sell, offer to sell, enter into any agreement to sell, or otherwise dispose of, any debt securities issued by the Company which are substantially similar to the Notes or securities convertible into such debt securities which are substantially similar to the Notes for a period of 30 days after the date of this prospectus supplement without first obtaining the written consent of the representatives. This consent may be given at any time without public notice.

Listing

The Notes are a new issue of securities with no established trading market. We intend to list the Notes on the NYSE. We expect trading in the Notes on the NYSE to begin within 30 days after the original issue date under the symbol “HTGX.” Currently there is no public market for the Notes.

We have been advised by the underwriters that they presently intend to make a market in the Notes after completion of the offering as permitted by applicable laws and regulations. The underwriters are not obligated, however, to make a market in the Notes and any such market-making may be discontinued at any time in the sole discretion of the underwriters without any notice. Accordingly, no assurance can be given as to the liquidity of, or development of a public trading market for, the Notes. If an active public trading market for the Notes does not develop, the market price and liquidity of the Notes may be adversely affected.

Price Stabilization, Short Positions

In connection with the offering, the underwriters may purchase and sell Notes in the open market. These transactions may include overallotment, covering transactions and stabilizing transactions. Overallotment involves sales of securities in excess of the aggregate principal amount of securities to be purchased by the underwriters in the offering, which creates a short position for the underwriters. Covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover short positions. Stabilizing transactions consist of certain bids or purchases of securities made for the purpose of preventing or retarding a decline in the market price of the securities while the offering is in progress.

The underwriters also may impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased Notes sold by or for the account of such underwriter in stabilizing or short covering transactions.

Any of these activities may cause the price of the Notes to be higher than the price that otherwise would exist in the open market in the absence of such transactions. These transactions may be affected in the over-the-counter market or otherwise and, if commenced, may be discontinued at any time without any notice relating thereto.

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Electronic Offer, Sale and Distribution of Notes

The underwriters may make prospectuses available in electronic (PDF) format. A prospectus in electronic (PDF) format may be made available on a web site maintained by the underwriters, and the underwriters may distribute such prospectuses electronically. The underwriters may allocate a limited principal amount of the Notes for sale to their online brokerage customers.

Other Relationships

The underwriters and their affiliates have provided in the past and may provide from time to time in the future in the ordinary course of their business certain commercial banking, financial advisory, investment banking and other services to Hercules or our portfolio companies for which they have received or will be entitled to receive separate fees. In particular, the underwriters or their affiliates may execute transactions with Hercules or on behalf of Hercules or any of our portfolio companies.

The underwriters or their affiliates may also trade in our securities, securities of our portfolio companies or other financial instruments related thereto for their own accounts or for the account of others and may extend loans or financing directly or through derivative transactions to us or any of our portfolio companies.

We may purchase securities of third parties from the underwriters or their affiliates after the offering. However, we have not entered into any agreement or arrangement regarding the acquisition of any such securities, and we may not purchase any such securities. We would only purchase any such securities if—among other things—we identified securities that satisfied our investment needs and completed our due diligence review of such securities.

After the date of this prospectus supplement, the underwriters and their affiliates may from time to time obtain information regarding specific portfolio companies or us that may not be available to the general public. Any such information is obtained by the underwriters and their affiliates in the ordinary course of its business and not in connection with the offering of the Notes. In addition, after the offering period for the sale of the Notes, the underwriters or their affiliates may develop analyses or opinions related to Hercules or our portfolio companies and buy or sell interests in one or more of our portfolio companies on behalf of their proprietary or client accounts and may engage in competitive activities. There is no obligation on behalf of these parties to disclose their respective analyses, opinions or purchase and sale activities regarding any portfolio company or regarding us to our noteholders or any other persons.

In the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. Certain of the underwriters and their affiliates that have a lending relationship with us routinely hedge their credit exposure to us consistent with their customary risk management policies. Typically, such underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the Notes offered hereby. Any such short positions could adversely affect future trading prices of the Notes offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

The principal business address of Keefe, Bruyette & Woods, Inc. is 787 7th Avenue, Fifth Floor, New York, New York 10019. The principal business address of Jefferies LLC is 520 Madison Avenue, New York, NY 10022. The principal business address of RBC Capital Markets, LLC is 3 World Financial Center, 200 Vesey Street, 8th Floor, New York, NY 10281.

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Other Jurisdictions

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the Notes offered by this prospectus supplement in any jurisdiction where action for that purpose is required. The Notes offered by this prospectus supplement may not be offered or sold, directly or indirectly, nor may this prospectus supplement or any other offering material or advertisements in connection with the offer and sale of any such Notes be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus supplement comes are advised to inform themselves about and to observe any restriction relating to the offering and the distribution of this prospectus supplement. This prospectus supplement and the accompanying prospectus do not constitute an offer to sell or a solicitation of an offer to buy the Notes offered by this prospectus supplement and the accompanying prospectus in any jurisdiction in which such an offer or a solicitation is unlawful.

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UNITED STATES FEDERAL INCOME TAX CONSEQUENCES

The following discussion is a general summary of the material U.S. federal income tax considerations (and, in the case of a non-U.S. holder (as defined below), the material U.S. federal estate tax consequences) applicable to an investment in the Notes. This summary does not purport to be a complete description of the income and estate tax considerations applicable to such an investment. The discussion is based upon the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations, and administrative and judicial interpretations, each as of the date of this prospectus supplement and all of which are subject to change, potentially with retroactive effect. You should consult your own tax advisor with respect to tax considerations that pertain to your purchase of our Notes.

This discussion deals only with Notes held as capital assets within the meaning of Section 1221 of the Code and does not purport to deal with persons in special tax situations, such as financial institutions, insurance companies, controlled foreign corporations, passive foreign investment companies and regulated investment companies (and shareholders of such corporations), dealers in securities or currencies, traders in securities, former citizens of the United States, persons holding the Notes as a hedge against currency risks or as a position in a “straddle,” “hedge,” “constructive sale transaction” or “conversion transaction” for tax purposes, entities that are tax-exempt for U.S. federal income tax purposes, retirement plans, individual retirement accounts, tax-deferred accounts, persons subject to the alternative minimum tax, pass-through entities (including partnerships and entities and arrangements classified as partnerships for U.S. federal income tax purposes) and beneficial owners of pass-through entities, or persons whose functional currency is not the U.S. dollar. It also does not deal with beneficial owners of the Notes other than original purchasers of the Notes who acquire the Notes in this offering for a price equal to their original issue price (i.e., the first price at which a substantial amount of the Notes is sold other than to bond houses, brokers, or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers). If you are considering purchasing the Notes, you should consult your own tax advisor concerning the application of the U.S. federal income tax laws to you in light of your particular situation, as well as any consequences to you of purchasing, owning and disposing of the Notes under the laws of any other taxing jurisdiction.

For purposes of this discussion, the term “U.S. holder” means a beneficial owner of a Note that is, for U.S. federal income tax purposes, (i) an individual citizen or resident of the United States, (ii) a corporation or other entity treated as a corporation for U.S. federal income tax purposes, created or organized in or under the laws of the United States or of any political subdivision thereof, (iii) a trust (a) subject to the control of one or more U.S. persons and the primary supervision of a court in the United States, or (b) that existed on August 20, 1996 and has made a valid election (under applicable Treasury Regulations) to be treated as a domestic trust, or (iv) an estate the income of which is subject to U.S. federal income taxation regardless of its source. The term “non-U.S. holder” means a beneficial owner of a Note that is neither a U.S. holder nor a partnership (including an entity or arrangement treated as a partnership for U.S. federal income tax purposes).

If a partnership (including an entity or arrangement treated as a partnership for U.S. federal income tax purposes) holds any Notes, the U.S. federal income tax treatment of a partner of the partnership generally will depend upon the status of the partner, the activities of the partnership and certain determinations made at the partner level. Partnerships holding Notes, and the persons holding interests in such partnerships, should consult their own tax advisors as to the consequences of investing in the Notes in their individual circumstances.

Taxation of Note Holders

Taxation of U.S. Holders. Payments or accruals of interest on a Note generally will be taxable to a U.S. holder as ordinary interest income at the time they are received (actually or constructively) or accrued, in accordance with the U.S. holder’s regular method of tax accounting.

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Upon the sale, exchange, redemption, retirement or other taxable disposition of a Note, a U.S. holder generally will recognize capital gain or loss equal to the difference between the amount realized on the sale, exchange, redemption, retirement or other taxable disposition (excluding amounts representing accrued and unpaid interest, which are treated as ordinary income to the extent not previously included in income) and the U.S. holder’s adjusted tax basis in the Note. A U.S. holder’s adjusted tax basis in a Note generally will equal the U.S. holder’s initial investment in the Note. Capital gain or loss generally will be long-term capital gain or loss if the U.S. holder’s holding period in the Note was more than one year. Long-term capital gains generally are taxed at reduced rates for individuals and certain other non-corporate U.S. holders and the deductibility of capital losses is subject to limitations.

Taxation of Non-U.S. Holders. A non-U.S. holder generally will not be subject to U.S. federal income or withholding taxes on payments of principal or interest on a Note provided that (i) income on the Note is not effectively connected with the conduct by the non-U.S. holder of a trade or business within the United States, (ii) the non-U.S. holder is not a controlled foreign corporation related to the Company through stock ownership, (iii) in the case of interest income, the non-U.S. holder is not a bank receiving interest described in Section 881(c)(3)(A) of the Code, (iv) the non-U.S. holder does not own (directly or indirectly, actually or constructively) 10% or more of the total combined voting power of all classes of stock of the Company, and (v) the non-U.S. holder provides a statement in the year in which a payment occurs or in the preceding 3 years, on an Internal Revenue Service (IRS) Form W-8BEN, Form W-8BEN-E, or other applicable form signed under penalties of perjury that includes its name and address and certifies that the non-U.S. holder is the beneficial owner and is not a U.S. person in compliance with applicable requirements, or satisfies documentary evidence requirements for establishing that it is a non-U.S. holder.

A non-U.S. holder that is not exempt from tax under these rules generally will be subject to U.S. federal income tax withholding on payments of interest on the Notes at a rate of 30% unless (i) the income is effectively connected with the conduct of a U.S. trade or business, so long as the non-U.S. holder has provided an IRS Form W-8ECI or substantially similar substitute form stating that the interest on the Notes is effectively connected with the non-U.S. holder’s conduct of a trade or business in the U.S. in which case the interest will be subject to U.S. federal income tax on a net income basis as applicable to U.S. holders generally (unless an applicable income tax treaty provides otherwise), or (ii) an applicable income tax treaty provides for a lower rate of, or exemption from, withholding tax. To claim the benefit of an income tax treaty or to claim exemption from withholding because income is effectively connected with a U.S. trade or business, the non-U.S. holder must timely provide the appropriate, properly executed IRS forms. These forms may be required to be periodically updated.

In the case of a non-U.S. holder that is a corporation and that receives income that is effectively connected with the conduct of a U.S. trade or business, such income may also be subject to a branch profits tax (which is generally imposed on a non-U.S. corporation on the actual or deemed repatriation from the United States of earnings and profits attributable to a U.S. trade or business) at a 30% rate. The branch profits tax may not apply (or may apply at a reduced rate) if the non-U.S. holder is a qualified resident of a country with which the United States has an income tax treaty.

Generally, a non-U.S. holder will not be subject to U.S. federal income or withholding taxes on any amount that constitutes capital gain upon the sale, exchange, redemption, retirement or other taxable disposition of a Note, provided that the gain is not effectively connected with the conduct of a trade or business in the United States by the non-U.S. holder (and, if required by an applicable income tax treaty, is not attributable to a United States “permanent establishment” maintained by the non-U.S. holder). Non-U.S. holders should consult their own tax advisors with regard to whether taxes will be imposed on capital gain in their individual circumstances.

A Note that is held by an individual who, at the time of death, is not a citizen or resident of the United States (as specially defined for U.S. federal estate tax purposes) generally will not be subject to the U.S. federal estate tax, unless, at the time of death, (i) such individual directly or indirectly, actually or constructively, owns ten percent or more of the total combined voting power of all classes of our stock entitled to vote within the meaning

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of Section 871(h)(3) of the Code and the Treasury Regulations thereunder or (ii) such individual’s interest in the Notes is effectively connected with the individual’s conduct of a U.S. trade or business.

Information Reporting and Backup Withholding. A U.S. holder (other than an “exempt recipient,” including a corporation and certain other persons who, when required, demonstrate their exempt status) may be subject to backup withholding on, and to information reporting requirements with respect to, payments of principal and interest on, and proceeds from the sale, exchange, redemption or retirement of, the Notes. In general, if a non-corporate U.S. holder subject to information reporting fails to furnish a correct taxpayer identification number or otherwise fails to comply with applicable backup withholding requirements, backup withholding at the applicable rate may apply.

The amount of interest we pay to a non-U.S. holder on the Notes will be reported to such non-U.S. Holder and to the IRS annually on an IRS Form 1042-S even if the non-U.S. holder is exempt from the withholding tax described above. Copies of the information returns reporting those payments and the amounts withheld, if any, may also be made available to the tax authorities in the country where the non-U.S. holder is resident under provisions of an applicable income tax treaty or agreement.

In addition, backup withholding tax and certain other information reporting requirements apply to payments of principal and interest on, and proceeds from the sale, exchange, redemption or retirement of, the Notes held by a non-U.S. holder, unless an exemption applies. Backup withholding and information reporting will not apply to payments we make to a non-U.S. holder if such non-U.S. holder has provided to the applicable withholding agent under penalties of perjury the required certification of their non-U.S. person status as discussed above (and the applicable withholding agent does not have actual knowledge or reason to know that they are a U.S. person) or if the non-U.S. holder is an exempt recipient.

If a non-U.S. holder sells or redeems a Note through a U.S. broker or the U.S. office of a foreign broker, the proceeds from such sale or redemption will be subject to information reporting and backup withholding unless such non-U.S. holder provides a withholding certificate or other appropriate documentary evidence establishing that such non-U.S. holder is not a U.S. person to the broker and such broker does not have actual knowledge or reason to know that such non-U.S. holder is a U.S. person, or the non-U.S. holder is an exempt recipient eligible for an exemption from information reporting and backup withholding. If a non-U.S. holder sells or redeems a Note through the foreign office of a broker who is a U.S. person or has certain enumerated connections with the United States, the proceeds from such sale or redemption will be subject to information reporting unless the non-U.S. holder provides to such broker a withholding certificate or other appropriate documentary evidence establishing that the non-U.S. holder is not a U.S. person and such broker does not have actual knowledge or reason to know that such evidence is false, or the non-U.S. holder is an exempt recipient eligible for an exemption from information reporting. In circumstances where information reporting by the foreign office of such a broker is required, backup withholding will be required only if the broker has actual knowledge that the non-U.S. holder is a U.S. person.

You should consult your tax advisor regarding the qualification for an exemption from backup withholding and information reporting and the procedures for obtaining such an exemption, if applicable. Any amounts withheld under the backup withholding rules from a payment to a beneficial owner generally would be allowed as a refund or a credit against such beneficial owner’s U.S. federal income tax provided the required information is timely furnished to the IRS.

Medicare Tax on “Net Investment Income.” A tax of 3.8% will be imposed on certain “net investment income” (or “undistributed net investment income”, in the case of estates and trusts) received by taxpayers with adjusted gross income above certain threshold amounts. “Net investment income” as defined for U.S. federal Medicare contribution purposes generally includes interest payments and gain recognized from the sale or other

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disposition of the Notes. Tax-exempt trusts, which are not subject to income taxes generally, and foreign individuals will not be subject to this tax. U.S. holders should consult their own tax advisors regarding the effect, if any, of this tax on their ownership and disposition of the Notes.

Foreign Account Tax Compliance Act. A withholding tax of 30% is imposed on payments of interest on a debt instrument paid to certain non-U.S. entities, including certain foreign financial institutions and investment funds, unless such non-U.S. entity complies with certain reporting requirements regarding its U.S. account holders and its U.S. owners. In addition, payments of gross proceeds from the disposition of a debt instrument paid to certain non-U.S. entities listed above may also be subject to withholding starting on January 1, 2017. Investors considering purchasing the Notes should consult their own tax advisors regarding the effect, if any, of these withholding and reporting provisions.

You should consult your own tax advisor with respect to the particular tax consequences to you of an investment in the Notes, including the possible effect of any pending legislation or proposed regulations.

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LEGAL MATTERS

Certain legal matters in connection with the securities offered hereby will be passed upon for us by Sutherland Asbill & Brennan LLP, Washington, DC. Certain legal matters in connection with the securities offered hereby will be passed upon for the underwriters by Fried, Frank, Harris, Shriver & Jacobson LLP, New York, NY.

EXPERTS

The consolidated financial statements as of December 31, 2013 and 2012 and for each of the three years in the period ended December 31, 2013 and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) as of December 31, 2013 included in the accompanying prospectus have been so included in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

AVAILABLE INFORMATION

We have filed with the SEC a registration statement on Form N-2, together with all amendments and related exhibits, under the Securities Act, with respect to our securities offered by this prospectus supplement and the accompanying prospectus. The registration statement contains additional information about us and our securities being offered by this prospectus supplement and the accompanying prospectus.

We file annual, quarterly and current periodic reports, proxy statements and other information with the SEC under the Exchange Act. You may inspect and copy these reports, proxy statements and other information, as well as the registration statement of which this prospectus supplement and accompanying prospectus form a part and the related exhibits and schedules, at the Public Reference Room of the SEC at 100 F Street, N.E., Washington, D.C. 20549-0102. You may obtain information on the operation of the Public Reference Room by calling the SEC at 202-551-8090. The SEC maintains an Internet website that contains reports, proxy and information statements and other information filed electronically by us with the SEC which are available on the SEC’s Internet website at http://www.sec.gov. Copies of these reports, proxy and information statements and other information may be obtained, after paying a duplicating fee, by electronic request at the following E-mail address: publicinfo@sec.gov, or by writing the SEC’s Public Reference Section, Washington, D.C. 20549-0102.

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$400,000,000

Common Stock

Preferred Stock

Warrants

Subscription Rights

Debt Securities

This prospectus relates to the offer, from time to time, in one or more offerings or series, up to $400,000,000 of shares of our common stock, par value $0.001 per share, preferred stock, par value $0.001 per share, warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, subscription rights or debt securities, which we refer to, collectively, as the “securities.” The preferred stock, debt securities, subscription rights and warrants offered hereby may be convertible or exchangeable into shares of our common stock. We may sell our securities through underwriters or dealers, “at-the-market” to or through a market maker into an existing trading market or otherwise directly to one or more purchasers, including existing stockholders in a rights offering, or through agents or through a combination of methods of sale, including auctions. The identities of such underwriters, dealers, market makers or agents, as the case may be, will be described in one or more supplements to this prospectus. The securities may be offered at prices and on terms to be described in one or more supplements to this prospectus.

Although we are not currently authorized to issue shares of our common stock at a price below our net asset value per share, we may seek stockholder approval of this proposal again at a special meeting of stockholders or our next annual meeting of stockholders. Our Board of Directors, subject to its fiduciary duties and regulatory requirements, has the discretion to determine the amount of the discount, and as a result, the discount could be up to 100% of net asset value per share. Sales of common stock at prices below net asset value per share dilute the interests of existing stockholders, have the effect of reducing our net asset value per share and may reduce our market price per share. In the event we offer common stock, the offering price per share will not be less than the net asset value per share of our common stock at the time we make the offering except (1) in connection with a rights offering to our existing stockholders, (2) with the consent of the holders of the majority of our voting securities and approval of our board of directors, or (3) under such circumstances as the Securities and Exchange Commission may permit. See “Risk Factors” for more information.

We are a specialty finance company focused on providing senior secured loans to venture capital-backed companies in technology-related markets, including technology, biotechnology, life science and energy and renewables technology industries at all stages of development. We primarily finance privately-held companies backed by leading venture capital and private equity firms and also may finance certain publicly-traded companies that lack access to public capital or are sensitive to equity ownership dilution. We source our investments through our principal office located in Palo Alto, CA, as well as additional offices in Boston, MA, New York, NY and McLean, VA. Our goal is to be the leading structured debt financing provider of choice for venture capital-backed companies in technology-related markets requiring sophisticated and customized financing solutions. We invest primarily in structured debt with warrants and, to a lesser extent, in senior debt and equity investments. We use the term “structured debt with warrants” to refer to any debt investment, such as a senior or subordinated secured loan, that is coupled with an equity component, including warrants, options or rights to purchase common or preferred stock. Our structured debt with warrants investments will typically be secured by select or all of the assets of the portfolio company. We invest primarily in private companies and to a lesser extent public companies.

Our investment objective is to maximize our portfolio total return by generating current income from our debt investments and capital appreciation from our equity-related investments. We are an internally-managed, non-diversified closed-end investment company that has elected to be regulated as a business development company under the Investment Company Act of 1940.

Our common stock is traded on the New York Stock Exchange, or NYSE, under the symbol “HTGC.” On May 23, 2014, the last reported sale price of a share of our common stock on the NYSE, was $14.77. The net asset value per share of our common stock at March 31, 2014 (the last date prior to the date of this prospectus on which we determined net asset value) was $10.58.

An investment in our securities may be speculative and involves risks including a heightened risk of total loss of investment. In addition, the companies in which we invest are subject to special risks. See “Risk Factors” beginning on page 11 to read about risks that you should consider before investing in our securities, including the risk of leverage.

Please read this prospectus before investing and keep it for future reference. It contains important information about us that a prospective investor ought to know before investing in our securities. We file annual, quarterly and current reports, proxy statements and other information about us with the Securities and Exchange Commission. The information is available free of charge by contacting us at 400 Hamilton Avenue, Suite 310, Palo Alto, California 94301 or by telephone calling collect at (650) 289-3060 or on our website at www.htgc.com. The SEC also maintains a website at www.sec.gov that contains such information.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus may not be used to consummate sales of any securities unless accompanied by a prospectus supplement.

The date of this prospectus is June 6, 2014

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission using the “shelf” registration process. Under the shelf registration process, which constitutes a delayed offering in reliance on Rule 415 under the Securities Act of 1933, as amended, we may offer, from time to time, up to $400,000,000 of our common stock, preferred stock, warrants representing rights to purchase shares of our common stock, preferred stock or debt securities, subscription rights or debt securities on the terms to be determined at the time of the offering. We may sell our securities through underwriters or dealers, “at-the-market” to or through a market maker, into an existing trading market or otherwise directly to one or more purchasers, including existing stockholders in a rights offering, or through agents or through a combination of methods of sale. The identities of such underwriters, dealers, market makers or agents, as the case may be, will be described in one or more supplements to this prospectus. The securities may be offered at prices and on terms described in one or more supplements to this prospectus. This prospectus provides you with a general description of the securities that we may offer. Each time we use this prospectus to offer securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. Please carefully read this prospectus and any such supplements together with the additional information described under “Where You Can Find Additional Information” in the “Summary” and “Risk Factors” sections before you make an investment decision.

A prospectus supplement may also add to, update or change information contained in this prospectus.

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1

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2

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3

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5

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FEES AND EXPENSES

The following table is intended to assist you in understanding the various costs and expenses that an investor in our common stock will bear directly or indirectly. However, we caution you that some of the percentages indicated in the table below are estimates and may vary. The footnotes to the fee table state which items are estimates. Except where the context suggests otherwise, whenever this prospectus contains a reference to fees or expenses paid by “you” or “us” or that “we” will pay fees or expenses, stockholders will indirectly bear such fees or expenses as investors in Hercules Technology Growth Capital, Inc.

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Example

The following example demonstrates the projected dollar amount of total cumulative expenses that would be incurred over various periods with respect to a hypothetical investment in our common stock. These amounts are based upon our payment of annual operating expenses at the levels set forth in the table above and assume no additional leverage.

The example and the expenses in the tables above should not be considered a representation of our future expenses, and actual expenses may be greater or lesser than those shown. Moreover, while the example assumes, as required by the applicable rules of the SEC, a 5% annual return, our performance will vary and may result in a return greater or lesser than 5%. In addition, while the example assumes reinvestment of all dividends and distributions at net asset value, participants in our dividend reinvestment plan may receive shares valued at the market price in effect at that time. This price may be at, above or below net asset value. See “Dividend Reinvestment Plan” for additional information regarding our dividend reinvestment plan.

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SELECTED CONSOLIDATED FINANCIAL DATA

The selected consolidated financial data should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Senior Securities” and the consolidated financial statements and related notes included elsewhere herein. The selected balance sheet data as of the end of fiscal year 2013, 2012, 2011 and 2010 and the financial statement of operations data for fiscal 2013, 2012, 2011 and 2010 has been derived from our audited financial statements, which have been audited by PricewaterhouseCoopers LLP, our independent registered public accounting firm.” The historical data are not necessarily indicative of results to be expected for any future period. The selected financial and other data for the three months ended March 31, 2014 and other quarterly financial information is derived from our unaudited financial statements, but in the opinion of management, reflects all adjustments (consisting only of normal recurring adjustments) that are necessary to present fairly the results of such interim periods. Interim results as of and for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014.

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The following tables set forth certain quarterly financial information for each of the nine quarters up to and ending March 31, 2014. This information was derived from our unaudited consolidated financial statements. Results for any quarter are not necessarily indicative of results for the full year or for any future quarter.

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RISK FACTORS

Investing in our securities involves a number of significant risks. Before you invest in our securities, you should be aware of various risks, including those described below in this prospectus and those set forth in any prospectus supplement accompanying this prospectus. You should carefully consider these risk factors, together with all of the other information included in this prospectus and the supplement accompanying this prospectus, before you decide whether to make an investment in our common stock. The risks set out below and in this prospectus are not the only risks we face. Additional risks and uncertainties not presently known to us or not presently deemed material by us may also impair our operations and performance. If any of the following events occur, our business, financial condition, results of operations and cash flows could be materially and adversely affected. In such case, our net asset value and the trading price of our common stock could decline and you may lose all or part of your investment. The risk factors described below, together with those set forth in any prospectus supplement accompanying this prospectus, are the principal risk factors associated with an investment in our common stock, as well as those factors generally associated with an investment company with investment objectives, investment policies, capital structure or trading markets similar to ours.

Risks Related to our Business Structure

We are dependent upon key management personnel for their time availability and for our future success, particularly Manuel A. Henriquez, and if we are not able to hire and retain qualified personnel, or if we lose any member of our senior management team, our ability to implement our business strategy could be significantly harmed.

We depend upon the members of our senior management, particularly Mr. Henriquez, as well as other key personnel for the identification, final selection, structuring, closing and monitoring of our investments. These employees have critical industry experience and relationships on which we rely to implement our business plan. If we lose the services of Mr. Henriquez, or of any other senior management members, we may not be able to operate the business as we expect, and our ability to compete could be harmed, which could cause our operating results to suffer. Furthermore, we do not have an employment agreement with Mr. Henriquez and our senior management is not restricted from creating new investment vehicles subject to compliance with applicable law. We believe our future success will depend, in part, on our ability to identify, attract and retain sufficient numbers of highly skilled employees. If we do not succeed in identifying, attracting and retaining such personnel, we may not be able to operate our business as we expect.

Our business model depends to a significant extent upon strong referral relationships with venture capital and private equity fund sponsors, and our inability to develop or maintain these relationships, or the failure of these relationships to generate investment opportunities, could adversely affect our business.

We expect that members of our management team will maintain their relationships with venture capital and private equity firms, and we will rely to a significant extent upon these relationships to provide us with our deal flow. If we fail to maintain our existing relationships, our relationships become strained as a result of enforcing our rights with respect to non-performing portfolio companies in protecting our investments or we fail to develop new relationships with other firms or sources of investment opportunities, then we will not be able to grow our investment portfolio. In addition, persons with whom members of our management team have relationships are not obligated to provide us with investment opportunities and, therefore, there is no assurance that such relationships will lead to the origination of debt or other investments.

We operate in a highly competitive market for investment opportunities, and we may not be able to compete effectively.

A number of entities compete with us to make the types of investments that we plan to make in prospective portfolio companies. We compete with a large number of venture capital and private equity firms, as well as with

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other investment funds, business development companies, investment banks and other sources of financing, including traditional financial services companies such as commercial banks and finance companies. Many of our competitors are substantially larger and have considerably greater financial, technical, marketing and other resources than we do. For example, some competitors may have a lower cost of funds and/or access to funding sources that are not available to us. This may enable some competitors to make commercial loans with interest rates that are comparable to or lower than the rates that we typically offer. A significant increase in the number and/or the size of our competitors, including traditional commercial lenders and other financing sources, in technology-related industries could force us to accept less attractive investment terms. We may miss opportunities if we do not match competitors’ pricing, terms and structure. If we do match competitors’ pricing, terms or structure, we may experience decreased net interest income and increased risk of credit losses. In addition, some of our competitors may have higher risk tolerances or different risk assessments, which could allow them to consider a wider variety of investments, establish more relationships and build their market shares. Furthermore, many potential competitors are not subject to the regulatory restrictions that the 1940 Act imposes on us as a business development company or that the Code imposes on us as a RIC. If we are not able to compete effectively, our business, financial condition, and results of operations will be adversely affected. As a result of this competition, there can be no assurance that we will be able to identify and take advantage of attractive investment opportunities, or that we will be able to fully invest our available capital.

If we are unable to manage our future growth effectively, we may be unable to achieve our investment objective, which could adversely affect our financial condition and results of operations and cause the value of your investment to decline.

Our ability to achieve our investment objective will depend on our ability to sustain growth. Sustaining growth will depend, in turn, on our senior management team’s ability to identify, evaluate, finance and invest in suitable companies that meet our investment criteria. Accomplishing this result on a cost-effective basis is largely a function of our marketing capabilities, our management of the investment process, our ability to provide efficient services and our access to financing sources on acceptable terms. Failure to manage our future growth effectively could have a material adverse effect on our business, financial condition and results of operations.

Because we intend to distribute substantially all of our income to our stockholders in order to qualify as a RIC, we will continue to need additional capital to finance our growth. If additional funds are unavailable or not available on favorable terms, our ability to grow will be impaired.

In order to satisfy the tax requirements applicable to a RIC, to avoid payment of excise taxes and to minimize or avoid payment of income taxes, we intend to distribute to our stockholders substantially all of our net ordinary income and realized net capital gains except for certain realized net capital gains, which we may retain, pay applicable income taxes with respect thereto and elect to treat as deemed distributions to our stockholders. As a business development company, we generally are required to meet a coverage ratio of total assets to total borrowings and other senior securities, which includes all of our borrowings and any preferred stock that we may issue in the future, of at least 200%. This requirement limits the amount that we may borrow. This limitation may prevent us from incurring debt and require us to raise additional equity at a time when it may be disadvantageous to do so. We cannot assure you that debt and equity financing will be available to us on favorable terms, or at all, and debt financings may be restricted by the terms of any of our outstanding borrowings. If we are unable to incur additional debt, we may be required to raise additional equity at a time when it may be disadvantageous to do so. In addition, shares of closed-end investment companies have recently traded at discounts to their net asset values. This characteristic of closed-end investment companies is separate and distinct from the risk that our net asset value per share may decline. We cannot predict whether shares of our common stock will trade above, at or below our net asset value. If our common stock trades below its net asset value, we generally will not be able to issue additional shares of our common stock at its market price without first obtaining the approval for such issuance from our stockholders and our independent directors. If additional funds are not available to us, we could be forced to curtail or cease new lending and investment activities, and our net asset value could decline. In addition, our results of operations and financial condition could be adversely affected.

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Because we have substantial indebtedness, there could be increased risk in investing in our company.

Lenders have fixed dollar claims on our assets that are superior to the claims of stockholders, and we have granted, and may in the future grant, lenders a security interest in our assets in connection with borrowings. In the case of a liquidation event, those lenders would receive proceeds before our stockholders. In addition, borrowings, also known as leverage, magnify the potential for gain or loss on amounts invested and, therefore, increase the risks associated with investing in our securities. Leverage is generally considered a speculative investment technique. If the value of our assets increases, then leveraging would cause the net asset value attributable to our common stock to increase more than it otherwise would have had we not leveraged. Conversely, if the value of our assets decreases, leveraging would cause the net asset value attributable to our common stock to decline more than it otherwise would have had we not leveraged. Similarly, any increase in our revenue in excess of interest expense on our borrowed funds would cause our net income to increase more than it would without the leverage. Any decrease in our revenue would cause our net income to decline more than it would have had we not borrowed funds and could negatively affect our ability to make distributions on common stock. Our ability to service any debt that we incur will depend largely on our financial performance and will be subject to prevailing economic conditions and competitive pressures. We and, indirectly, our stockholders will bear the cost associated with our leverage activity. If we are not able to service our substantial indebtedness, our business could be harmed materially.

Our secured credit facilities with Wells Fargo Capital Finance LLC (the “Wells Facility”) and Union Bank, N.A. (the “Union Bank Facility,” and together with the Wells Facility, our “Credit Facilities”) our Convertible Senior Notes, our 2019 Notes and our Asset-Backed Notes (as each term is defined below) contain financial and operating covenants that could restrict our business activities, including our ability to declare dividends if we default under certain provisions.

As of March 31, 2014, we did not have any outstanding borrowings under our Credit Facilities. In addition, as of March 31, 2014, we had approximately $190.2 million of indebtedness outstanding incurred by our SBIC subsidiaries, approximately $75.0 million of Convertible Senior Notes payable, approximately $170.4 million of 2019 Notes and approximately $63.8 million in aggregate principal amount of fixed rate asset-backed notes (the “Asset-Backed Notes”) in connection with our $230.7 million debt Securitization (the “Debt Securitization”). There can be no assurance that we will be successful in obtaining any additional debt capital on terms acceptable to us or at all. If we are unable to obtain debt capital, then our equity investors will not benefit from the potential for increased returns on equity resulting from leverage to the extent that our investment strategy is successful and we may be limited in our ability to make new commitments or fundings to our portfolio companies.

As a business development company, generally, we are not permitted to incur indebtedness unless immediately after such borrowing we have an asset coverage for total borrowings of at least 200% (i.e., the amount of debt may not exceed 50% of the value of our assets). In addition, we may not be permitted to declare any cash dividend or other distribution on our outstanding common shares, or purchase any such shares, unless, at the time of such declaration or purchase, we have an asset coverage of at least 200% after deducting the amount of such dividend, distribution, or purchase price. If this ratio declines below 200%, we may not be able to incur additional debt and may need to sell a portion of our investments to repay some debt when it is disadvantageous to do so, and we may not be able to make distributions. As of March 31, 2014 our asset coverage ratio under our regulatory requirements as a business development company was 312.8%, excluding our SBIC debentures as a result of our exemptive order from the SEC which allows us to exclude all SBA leverage from our asset coverage ratio.

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Illustration. The following table illustrates the effect of leverage on returns from an investment in our common stock assuming various annual returns, net of expenses. The calculations in the table below are hypothetical and actual returns may be higher or lower than those appearing below.

It is likely that the terms of any current or future long-term or revolving credit or warehouse facility we may enter into in the future could constrain our ability to grow our business.

Under our borrowings and our Credit Facilities, current lenders have, and any future lender or lenders may have, fixed dollar claims on our assets that are senior to the claims of our stockholders and, thus, will have a preference over our stockholders with respect to our assets in the collateral pool. Our Credit Facilities and borrowings also subject us to various financial and operating covenants, including, but not limited to, maintaining certain financial ratios and minimum tangible net worth amounts. Future credit facilities and borrowings will likely subject us to similar or additional covenants. In addition, we may grant a securities interest in our assets in connection with any such credit facilities and borrowings.

Our Credit Facilities generally contain customary default provisions such as a minimum net worth amount, a profitability test, and a restriction on changing our business and loan quality standards. In addition, our Credit Facilities require or are expected to require the repayment of all outstanding debt on the maturity which may disrupt our business and potentially the business of our portfolio companies that are financed through the facilities. An event of default under these facilities would likely result, among other things, in termination of the availability of further funds under the facilities and accelerated maturity dates for all amounts outstanding under the facilities, which would likely disrupt our business and, potentially, the business of the portfolio companies whose loans we finance through the facilities. This could reduce our revenues and, by delaying any cash payment allowed to us under our facilities until the lender has been paid in full, reduce our liquidity and cash flow and impair our ability to grow our business and our ability to make distributions sufficient to maintain our status as a RIC.

The terms of future available financing may place limits on our financial and operation flexibility. If we are unable to obtain sufficient capital in the future, we may be forced to reduce or discontinue our operations, not be able to make new investments, or otherwise respond to changing business conditions or competitive pressures.

In addition to regulatory requirements that restrict our ability to raise capital, our Credit Facilities, the Convertible Senior Notes and the 2019 Notes contain various covenants which, if not complied with, could accelerate repayment under the facility or require us to repurchase the Convertible Senior Notes and the 2019 Notes thereby materially and adversely affecting our liquidity, financial condition, results of operations and ability to pay dividends.

The credit agreements governing our Credit Facilities, the Convertible Senior Notes and the 2019 Notes require us to comply with certain financial and operational covenants. These covenants require us to, among other things, maintain certain financial ratios, including asset coverage, debt to equity and interest coverage. Our ability to continue to comply with these covenants in the future depends on many factors, some of which are beyond our control. There are no assurances that we will be able to comply with these covenants. Failure to comply with these covenants would result in a default which, if we were unable to obtain a waiver from the

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Index to Financial Statements

lenders under our Credit Facilities or the trustee or holders under the Convertible Senior Notes and could accelerate repayment under the facilities or the Convertible Senior Notes or the 2019 Notes and thereby have a material adverse impact on our liquidity, financial condition, results of operations and ability to pay dividends. In addition, holders of the Convertible Senior Notes will have the right to require us to repurchase the Convertible Senior Notes upon the occurrence of a fundamental change at a repurchase price equal to 100% of their principal amount, plus accrued and unpaid interest, if any. We may not have enough available cash or be able to obtain financing at the time we are required to make repurchases. See “Management’s Discussion and Analysis of Results of Operations and Financial Condition—Borrowings.”

We may be unable to obtain debt capital on favorable terms or at all, in which case we would not be able to use leverage to increase the return on our investments.

If we are unable to obtain debt capital, then our equity investors will not benefit from the potential for increased returns on equity resulting from leverage to the extent that our investment strategy is successful and we may be limited in our ability to make new commitments or fundings to our portfolio companies.

We are subject to certain risks as a result of our interests in connection with the Debt Securitization and our equity interest in the Securitization Issuer.

On December 19, 2012, in connection with the Debt Securitization and the offering of the Asset-Backed Notes by Hercules Capital Funding Trust 2012-1 (the “Securitization Issuer”), we sold and/or contributed to Hercules Capital Funding 2012-1 LLC, as Trust Depositor (the “Trust Depositor”), certain senior loans made to certain of our portfolio companies (the “Loans”), which the Trust Depositor in turn sold and/or contributed to the Securitization Issuer in exchange for 100% of the equity interest in the Securitization Issuer, cash proceeds and other consideration. Following these transfers, the Securitization Issuer, and not the Trust Depositor or us, held all of the ownership interest in the Loans.

As a result of the Debt Securitization, we hold, indirectly through the Trust Depositor, 100% of the equity interest in the Securitization Issuer. As a result, we consolidate the financial statements of the Trust Depositor and the Securitization Issuer, as well as our other subsidiaries, in our consolidated financial statements. Because each of the Trust Depositor and the Securitization Issuer is disregarded as an entity separate from its owner for U.S. federal income tax purposes, the sale or contribution by us to the Trust Depositor, and by the Trust Depositor to the Securitization Issuer, did not constitute a taxable event for U.S. federal income tax purposes. If the U.S. Internal Revenue Service were to take a contrary position, there could be a material adverse effect on our business, financial condition, results of operations or cash flows. Further, a failure of the Securitization Issuer to be treated as a disregarded entity for U.S. federal income tax purposes would constitute an event of default pursuant to the indenture under the Debt Securitization, upon which the trustee under the Debt Securitization (the “Trustee”) may and will at the direction of a supermajority of the holders of the Asset-Backed Notes (the “Noteholders”) declare the Asset-Backed Notes to be immediately due and payable and exercise remedies under the indenture, including (i) to institute proceedings for the collection of all amounts then payable on the Asset-Backed Notes or under the indenture, enforce any judgment obtained, and collect from the Securitization Issuer and any other obligor upon the Asset-Backed Notes monies adjudged due; (ii) institute proceedings from time to time for the complete or partial foreclosure of the indenture with respect to the property of the Securitization Issuer; (iii) exercise any remedies as a secured party under the relevant UCC and take other appropriate action under applicable law to protect and enforce the rights and remedies of the Trustee and the Noteholders; or (iv) sell the property of the Securitization Issuer or any portion thereof or rights or interest therein at one or more public or private sales called and conducted in any matter permitted by law. Any such exercise of remedies could have a material adverse effect on our business, financial condition, results of operations or cash flows.

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