Exhibit

Exhibit (d)(772)

FORM OF SUPPLEMENTAL INDENTURE

between

PROSPECT CAPITAL CORPORATION

and

U.S. BANK NATIONAL ASSOCIATION,

as Trustee

Dated as of the date set forth on Exhibit B hereto.

SUPPLEMENTAL INDENTURE

THIS SUPPLEMENTAL INDENTURE (this "Supplemental Indenture"), which shall be deemed the enumerated supplemental indenture as stated in Exhibit B hereto, is between Prospect Capital Corporation, a Maryland corporation (the "Company"), and U.S. Bank National Association, as trustee (the "Trustee"). All capitalized terms used herein shall have the meaning set forth in the Base Indenture (as defined below).

RECITALS OF THE COMPANY

The Company and the Trustee executed and delivered an Indenture, dated as of February 16, 2012, as amended by that certain Agreement of Resignation, Appointment and Acceptance, dated as of March 12, 2012, by and between the Company, the Trustee, and American Stock Transfer & Trust Company, LLC (the "Base Indenture" and, as supplemented by one or more supplemental indentures, including this Supplemental Indenture, the "Indenture"), to provide for the issuance by the Company from time to time of the Company's unsecured debentures, notes or other evidences of indebtedness (the "Securities"), to be issued in one or more series as provided in the Indenture.

The Company desires to issue and sell the aggregate principal amount as listed in Exhibit B hereto of the Company's senior notes as described in Exhibit B attached hereto (the "Notes").

Sections 9.01(5) and 9.01(7) of the Base Indenture provide that without the consent of Holders of the Securities of any series issued under the Indenture, the Company, when authorized by or pursuant to a Board Resolution, and the Trustee, at any time and from time to time, may enter into one or more indentures supplemental to the Base Indenture to (i) change or eliminate any of the provisions of the Indenture when there is no Security Outstanding of any series created prior to the execution of a supplemental indenture that is entitled to the benefit of such provision and (ii) establish the form or terms of Securities of any series as permitted by Section 2.01 and Section 3.01 of the Base Indenture.

The Company desires to establish the form and terms of the Notes and to modify, alter, supplement and change certain provisions of the Base Indenture for the benefit of the Holders of the Notes (except as may be provided in a future supplemental indenture to the Indenture ("Future Supplemental Indenture")).

The Company has duly authorized the execution and delivery of this Supplemental Indenture to provide for the issuance of the Notes and all acts and things necessary to make this Supplemental Indenture a valid, binding, and legal obligation of the Company and to constitute a valid agreement of the Company, in accordance with its terms, have been done and performed.

NOW, THEREFORE, THIS INDENTURE WITNESSETH:

For and in consideration of the premises and the purchase of the Notes by the Holders thereof, it is mutually agreed, for the equal and proportionate benefit of all Holders of the Notes, as follows:

ARTICLE I

TERMS OF THE NOTES

Section 1.01 Terms of the Notes. The following terms relating to the Notes are hereby established:

(a) The Notes shall constitute a series of Securities having the title as stated in Exhibit B hereto and shall be designated as Senior Securities under the Indenture. The Notes shall bear a CUSIP number and an ISIN number as stated in Exhibit B hereto.

(b) The aggregate principal amount of the Notes that may be initially authenticated and delivered under the Indenture (except for Notes authenticated and delivered upon registration of, transfer of, or in exchange for, or in lieu of, other Notes pursuant to Sections 3.04, 3.05, 3.06, 9.06 or 11.07 of the Base Indenture) shall be as stated in Exhibit B attached hereto. Under a Board Resolution, Officers' Certificate pursuant to Board Resolutions or an indenture supplement, the Company may from time to time, without the consent of the Holders of Notes, issue additional Notes (in any such case "Additional Notes") having the same ranking and the same interest rate, maturity and other terms as the Notes. Any Additional Notes and the existing Notes will constitute a single series under the Indenture and all references to the relevant Notes herein shall include the Additional Notes unless the context otherwise requires.

(c) The entire outstanding principal of the Notes shall be payable on the maturity date as identified on Exhibit B attached hereto.

(d) If the Notes are identified as "Fixed" on Exhibit B, the rate at which the Notes shall bear interest shall be the percentage per annum identified as the "Coupon Rate" on Exhibit B attached hereto; and if the Notes are identified as "Step" on Exhibit B, the rates at which the Notes shall bear interest shall be the percentages per annum during the corresponding periods as identified in the applicable footnote under the "Coupon Rate" on Exhibit B attached hereto (the "Applicable Interest Rate"). The date from which interest shall accrue on the Notes shall be on the date specified in Exhibit B attached hereto, or the most recent Interest Payment Date to which interest has been paid or provided for; the Interest Payment Dates for the Notes shall be as identified in Exhibit B attached hereto of each year, commencing on the date as identified as the 1^st Coupon Date in Exhibit B hereto (if an Interest Payment Date falls on a day that is not a Business Day, then the applicable interest payment will be made on the next succeeding Business Day and no additional interest will accrue as a result of such delayed payment); the initial interest period will be the period from and including the date as identified as the 1^st Coupon Date in Exhibit B hereto (or the most recent Interest Payment Date to which interest has been paid or provided for), to, but excluding, the initial Interest Payment Date, and the subsequent interest periods will be the periods from and including an Interest Payment Date to, but excluding, the next Interest Payment Date or the Stated Maturity, as the case may be; the interest so payable, and punctually paid or duly provided for, on any Interest Payment Date, will be paid to the Person in whose name the Note (or one or more predecessor Notes) is registered at the close of business on the Regular Record Date for such interest, which shall be the record

dates as identified in Exhibit B hereto (whether or not a Business Day), as the case may be, next preceding such Interest Payment Date. The initial interest payment on the Notes on the date as identified as the 1^st Coupon Date in Exhibit B hereto, or the initial Interest Payment Date, shall be equal to amount identified as the 1^st Coupon Amount in Exhibit B hereto. Payment of principal of (and premium, if any) and any such interest on the Notes will be made at the Corporate Trust Office of the Trustee in New York, New York in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Company payment of interest may be made by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register. Interest on the Notes will be computed on the basis of a 360-day year of twelve 30-day months.

(e) The Notes shall be initially issuable in global form (each such Note, a "Global Note"). The Global Notes and the Trustee's certificate of authentication thereon shall be substantially in the form of Exhibit A hereto. Each Global Note shall represent the outstanding Notes as shall be specified therein and each shall provide that it shall represent the aggregate amount of outstanding Notes from time to time endorsed thereon and that the aggregate amount of outstanding Notes represented thereby may from time to time be reduced or increased, as appropriate, to reflect exchanges and redemptions. Any endorsement of a Global Note to reflect the amount of any increase or decrease in the amount of outstanding Notes represented thereby shall be made by the Trustee or the Security Registrar, in accordance with Sections 2.03 and 3.05 of the Indenture.

(f) The depositary for such Global Notes (the "Depositary") shall be The Depository Trust Company, New York, New York. The Security Registrar with respect to the Global Notes shall be the Trustee.

(g) The Notes shall be defeasible pursuant to Section 14.02 or Section 14.03 of the Base Indenture. Covenant defeasance contained in Section 14.03 of the Base Indenture shall apply to the covenants contained in Sections 10.06 and 10.08 of the Indenture.

(h) The Notes shall be redeemable pursuant to Section 11.01 of the Base Indenture and as follows:

(i) The Notes will be redeemable in whole or in part at any time or from time to time, at the option of the Company, on or after the date identified as the Optional Redemption Date in Exhibit B hereto, at a redemption price of $1,000 per Note plus accrued and unpaid interest payments otherwise payable for the then-current quarterly interest period accrued to, but excluding, the date fixed for redemption.

(ii) Notice of redemption shall be given in writing and mailed, first-class postage prepaid or by overnight courier guaranteeing next-day delivery, to each Holder of the Notes to be redeemed, not less than thirty (30) nor more than sixty (60) days prior to the Redemption Date, at the Holder's address appearing in the Security

(iii) Any exercise of the Company's option to redeem the Notes will be done in compliance with the Investment Company Act.

(iv) If the Company elects to redeem only a portion of the Notes, the Trustee will determine the method for selecting the particular Notes to be redeemed, in accordance with the Investment Company Act.

(v) Unless the Company defaults in payment of the Redemption Price, on and after the Redemption Date, interest will cease to accrue on the Notes called for redemption hereunder.

(vi) The "Survivor's Option" is defined in Section 2.01 and, if applicable to the Notes, is a provision in a Note pursuant to which the Company agrees to repay that Note, if requested by the authorized representative of the beneficial owner of that Note, following the death of the beneficial owner of the Note, so long as the Note was owned by that beneficial owner or the estate of that beneficial owner at least six months prior to the request. The Survivor's Option, if applicable, shall be so specified under "Survivor's Option" on Exhibit B attached hereto.

Upon the valid exercise of any Survivor's Option and the proper tender of that Note for repayment, the Company will, at its option, repay or repurchase that Note, in whole or in part, at a price equal to 100% of the principal amount of the deceased beneficial owner's interest in that Note plus unpaid interest accrued to the date of repayment.

To be valid, any Survivor's Option must be exercised by or on behalf of the person who has authority to act on behalf of the deceased beneficial owner of the Note (including, without limitation, the personal representative or executor of the deceased beneficial owner or the surviving joint owner with the deceased beneficial owner) under the laws of the applicable jurisdiction.

The death of a person holding a beneficial ownership interest in a Note as a joint tenant or tenant by the entirety with another person, or as a tenant in common with the deceased holder's spouse, will be deemed the death of a beneficial owner of that Note, and the entire principal amount of the Note so held will be subject to repayment by us upon request. However, the death of a person holding a beneficial ownership interest in a Note as tenant in common with a person other than such deceased holder's spouse will be deemed the death of a beneficial owner only with respect to such deceased person's interest in the Note.

The death of a person who, during his or her lifetime, was entitled to substantially all of the beneficial ownership interests in a Note will be deemed the death of the beneficial owner of that Note for purposes of any Survivor's Option, regardless of whether that beneficial owner was the registered holder of that Note, if entitlement to those interests

can be established to the satisfaction of the Trustee. A beneficial ownership interest will be deemed to exist in typical cases of nominee ownership, ownership under the Uniform Transfers to Minors Act or Uniform Gifts to Minors Act, community property or other joint ownership arrangements between a husband and wife. In addition, a beneficial ownership interest will be deemed to exist in custodial and trust arrangements where one person has all of the beneficial ownership interests in the applicable Note during his or her lifetime.

The Company has the discretionary right to limit the aggregate principal amount of Notes as to which exercises of any Survivor's Option shall be accepted by us from authorized representatives of all deceased beneficial owners in any calendar year to an amount equal to the greater of $2,000,000 or 2% of the principal amount of all Notes outstanding as of the end of the most recent calendar year. The Company also has the discretionary right to limit to $250,000 in any calendar year the aggregate principal amount of Notes as to which exercises of any Survivor's Option shall be accepted by us from the authorized representative of any individual deceased beneficial owner of Notes in such calendar year. In addition, the Company will not permit the exercise of any Survivor's Option except in principal amounts of $1,000 and multiples of $1,000.

An otherwise valid election to exercise any Survivor's Option may not be withdrawn. Each election to exercise any Survivor's Option will be accepted in the order that elections are received by the Trustee, except for any Note the acceptance of which would contravene any of the limitations described in the preceding paragraph. Notes accepted for repayment through the exercise of any Survivor's Option normally will be repaid on the first interest payment date that occurs 20 or more calendar days after the date of the acceptance. For example, if the acceptance date of a Note tendered through a valid exercise of any Survivor's Option is September 1, 2011, and interest on that Note is paid monthly, the Company would normally, at its option, repay that Note on the interest payment date occurring on October 15, 2011, because the September 15, 2011 interest payment date would occur less than 20 days from the date of acceptance. Each tendered Note that is not accepted in any calendar year due to the application of any of the limitations described in the preceding paragraph will be deemed to be tendered in the following calendar year in the order in which all such Notes were originally tendered. If a Note tendered through a valid exercise of any Survivor's Option is not accepted, the Trustee will deliver a notice by first-class mail to the registered holder, at that holder's last known address as indicated in the Note register, that states the reason that Note has not been accepted for repayment.

With respect to Notes represented by a Global Note, DTC or its nominee is treated as the holder of the Notes and will be the only entity that can exercise any Survivor's Option for such Notes. To obtain repayment pursuant to exercise of any Survivor's Option for a Note, the deceased beneficial owner's authorized representative must provide the following items to the broker or other entity through which the beneficial interest in the Note is held by the deceased beneficial owner:

• a written instruction to such broker or other entity to notify DTC of the authorized representative's desire to obtain repayment pursuant to exercise of such Survivor's Option;

• appropriate evidence satisfactory to the Trustee (a) that the deceased was the beneficial owner of the Note at the time of death and his or her interest in the Note was owned by the deceased beneficial owner or his or her estate at least six months prior to the request for repayment, (b) that the death of the beneficial owner has occurred, (c) of the date of death of the beneficial owner, and (d) that the representative has authority to act on behalf of the beneficial owner;

• if the interest in the Note is held by a nominee of the deceased beneficial owner, a certificate satisfactory to the Trustee from the nominee attesting to the deceased's beneficial ownership of such Note;

• written request for repayment signed by the authorized representative of the deceased beneficial owner with the signature guaranteed by a member firm of a registered national securities exchange or of the National Association of Securities Dealers, Inc. or a commercial bank or trust company having an office or correspondent in the United States;

• if applicable, a properly executed assignment or endorsement;

• tax waivers and any other instruments or documents that the Trustee reasonably requires in order to establish the validity of the beneficial ownership of the Note and the claimant's entitlement to payment; and

• any additional information the Trustee reasonably requires to evidence satisfaction of any conditions to the exercise of any Survivor's Option or to document beneficial ownership or authority to make the election and to cause the repayment of the Note.

In turn, the broker or other entity will deliver each of these items to the Trustee, together with evidence satisfactory to the Trustee from the broker or other entity stating that it represents the deceased beneficial owner.

The death of a person owning a Note in joint tenancy or tenancy by the entirety with another or others shall be deemed the death of the holder of the Note, and the entire principal amount of the Note so held shall be subject to repayment, together with interest accrued thereon to the repayment date. The death of a person owning a Note by tenancy in common shall be deemed the death of a holder of a Note only with respect to the deceased holder's interest in the Note so held by tenancy in common; except that in the event a Note is held by husband and wife as tenants in common, the death of either shall be deemed the death of the holder of the Note, and the entire principal amount of the Note so held shall be subject to repayment. The death of a person who, during his or her lifetime, was entitled to substantially all of the beneficial interests of ownership of a

Note, shall be deemed the death of the holder thereof for purposes of this provision, regardless of the registered holder, if such beneficial interest can be established to the satisfaction of the Trustee and us. Such beneficial interest shall be deemed to exist in typical cases of nominee ownership, ownership under the Uniform Gifts to Minors Act, the Uniform Transfers to Minors Act, community property or other joint ownership arrangements between a husband and wife and trust arrangements where one person has substantially all of the beneficial ownership interest in the Note during his or her lifetime.

The Company retains the right to limit the aggregate principal amount of Notes as to which exercises of any Survivor's Option applicable to the Notes will be accepted in any one calendar year as described above. All other questions regarding the eligibility or validity of any exercise of any Survivor's Option will be determined by the Trustee, in its sole discretion, which determination will be final and binding on all parties.

(i) The Notes shall not be subject to any sinking fund pursuant to Section 12.01 of the Base Indenture.

(j) The Notes shall be issuable in denominations of $1,000 and integral multiples of $1,000 in excess thereof.

(k) Holders of the Notes will not have the option to have the Notes repaid prior to the Stated Maturity.

ARTICLE II

DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

Section 2.01 Except as may be provided in a Future Supplemental Indenture, for the benefit of the Holders of the Notes but no other series of Securities under the Indenture, whether now or hereafter issued and Outstanding, Article One of the Base Indenture shall be amended by adding the following defined terms to Section 1.01 in appropriate alphabetical sequence, as follows:

"'Exchange Act' means the Securities Exchange Act of 1934, as amended, and any statute successor thereto."

"'GAAP' means generally accepted accounting principles in the United States set forth in the opinions and pronouncements of the Accounting Principles Board of the American Institute of Certified Public Accountants, the opinions and pronouncements of the Public Company Accounting Oversight Board and the statements and pronouncements of the Financial Accounting Standards Board or in such other statements by such other entity as have been approved by a significant segment of the accounting profession in the United States, which are in effect from time to time."

"'Investment Company Act' means the Investment Company Act of 1940, as amended, and the rules, regulations and interpretations promulgated thereunder, to the extent applicable, and any statute successor thereto."

"Survivor's Option" means, where applicable, the right of a holder of a Note to require the Company to repay such Note prior to its Stated Maturity upon the death of the owner of such Note, subject to the provisions hereof relating to such option..

ARTICLE III

REMEDIES

Section 3.01 Intentionally left blank.

ARTICLE IV

COVENANTS

Section 4.01 Except as may be provided in a Future Supplemental Indenture, for the benefit of the Holders of the Notes but no other series of Securities under the Indenture, whether now or hereafter issued and Outstanding, Article Ten of the Base Indenture shall be amended by adding the following new Section 10.08 thereto, each as set forth below:

"Section 10.08 Section 18(a)(1)(A) of the Investment Company Act.

The Company hereby agrees that for the period of time during which Notes are Outstanding, the Company will not violate, whether or not it is subject to, Section 18(a)(1)(A) as modified by Section 61(a)(1) of the Investment Company Act or any successor provisions thereto of the Investment Company Act."

ARTICLE V

MISCELLANEOUS

Section 5.01 This Supplemental Indenture and the Notes shall be governed by and construed in accordance with the laws of the State of New York, without regard to principles of conflicts of laws that would cause the application of laws of another jurisdiction. This Supplemental Indenture is subject to the provisions of the Trust Indenture Act that are required to be part of the Indenture and shall, to the extent applicable, be governed by such provisions.

Section 5.02 In case any provision in this Supplemental Indenture or in the Notes shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

Section 5.03 This Supplemental Indenture may be executed in any number of counterparts, each of which will be an original, but such counterparts will together constitute but

one and the same Supplemental Indenture. The exchange of copies of this Supplemental Indenture and of signature pages by facsimile, .pdf transmission, email or other electronic means shall constitute effective execution and delivery of this Supplemental Indenture for all purposes. Signatures of the parties hereto transmitted by facsimile, .pdf transmission, email or other electronic means shall be deemed to be their original signatures for all purposes.

Section 5.04 The Base Indenture, as supplemented and amended by this Supplemental Indenture, is in all respects ratified and confirmed, and the Base Indenture and this Supplemental Indenture shall be read, taken and construed as one and the same instrument with respect to the Notes. All provisions included in this Supplemental Indenture supersede any conflicting provisions included in the Base Indenture with respect to the Notes, unless not permitted by law. The Trustee accepts the trusts created by the Indenture, as supplemented by this Supplemental Indenture, and agrees to perform the same upon the terms and conditions of the Indenture, as supplemented by this Supplemental Indenture.

Section 5.05 The provisions of this Supplemental Indenture shall become effective as of the date hereof.

Section 5.06 Notwithstanding anything else to the contrary herein, the terms and provisions of this Supplemental Indenture shall apply only to the Notes and shall not apply to any other series of Securities under the Indenture and this Supplemental Indenture shall not and does not otherwise affect, modify, alter, supplement or change the terms and provisions of any other series of Securities under the Indenture, whether now or hereafter issued and Outstanding.

Section 5.07 The recitals contained herein and in the Notes shall be taken as the statements of the Company, and the Trustee assumes no responsibility for their correctness. The Trustee makes no representations as to the validity or sufficiency of this Supplemental Indenture, the Notes or any Additional Notes, except that the Trustee represents that it is duly authorized to execute and deliver this Supplemental Indenture, authenticate the Notes and any Additional Notes and perform its obligations hereunder. The Trustee shall not be accountable for the use or application by the Company of the Notes or any Additional Notes or the proceeds thereof.

IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed as of the date first above written.

PROSPECT CAPITAL CORPORATION

By:
    Name:
    Title:

U.S. BANK NATIONAL ASSOCIATION, as Trustee

By:
    Name:
    Title:

EXHIBIT A

EXHIBIT B