EXECUTION VERSION
                                                                  EXHIBIT 10.5.3

                                    GUARANTY

      GUARANTY, dated as of August 31, 2005 (as amended from time to time, this
"Guaranty"), made by AMERICAN HOME MORTGAGE INVESTMENT CORP., a Maryland
corporation ("Guarantor"), in favor of GOLDMAN SACHS MORTGAGE COMPANY, a New
York limited partnership ("Buyer").

                                    RECITALS

      Reference is made to that certain Master Repurchase Agreement dated as of
August 31, 2005 (as amended from time to time, the "Repurchase Agreement"), by
and among American Home Mortgage Acceptance, Inc., a Maryland corporation, and
American Home Mortgage Corp., a New York corporation (each a "Seller", and
collectively "Sellers), and Buyer, pursuant to which Buyer agreed to enter into
transactions with Sellers upon the terms and subject to the conditions set forth
therein. It is a condition precedent to the obligation of Buyer to enter into
Transactions that Guarantor execute and deliver to Buyer this Guaranty.

      Now, therefore, in consideration of the premises and to induce Buyer to
enter into the Repurchase Agreement and engage in Transactions with Sellers, and
for other good and valuable consideration the receipt and sufficiency of which
is hereby acknowledged, Guarantor hereby agrees to guarantee Sellers'
obligations under the Repurchase Agreement, as may be amended from time to time.

      1. Defined Terms.

      (a) Unless otherwise defined herein, terms defined in the Repurchase
Agreement and used herein shall have the meanings given to them in the
Repurchase Agreement.

      (b) "Obligations" shall mean all obligations and liabilities of Sellers to
Buyer, whether direct or indirect, absolute or contingent, due or to become due,
or now existing or hereafter incurred, or whether for payment or for performance
(including, without limitation, Price Differential accruing after the Repurchase
Date for the Transactions and Price Differential accruing after the filing of
any petition in bankruptcy, or the commencement of any insolvency,
reorganization or like proceeding, relating to any Seller, whether or not a
claim for post filing or post petition interest is allowed in such proceeding),
which may arise under, or out of or in connection with the Facility Documents,
whether on account of Repurchase Price, Price Differential, reimbursement
obligations, fees, indemnities, costs, expenses (including, without limitation,
all fees and disbursements of counsel to Buyer that are required to be paid by
any Seller pursuant to the terms of such documents) or otherwise.

      (c) The words "hereof," "herein" and "hereunder" and words of similar
import when used in this Guaranty shall refer to this Guaranty as a whole and
not to any particular provision of this Guaranty, and section and paragraph
references are to this Guaranty unless otherwise specified.

      (d) The meanings given to terms defined herein shall be equally applicable
to both the singular and plural forms of such terms.

      2. Guaranty.


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      (a) Guarantor hereby, unconditionally and irrevocably, guarantees to Buyer
and its successors, indorsees, transferees and assigns, the prompt and complete
payment and performance by each Seller when due (whether at the stated maturity,
by acceleration or otherwise) of the Obligations.

      (b) Guarantor further agrees to pay any and all reasonable expenses
(including, without limitation, all reasonable fees and disbursements of
counsel) which may be paid or incurred by Buyer in enforcing, or obtaining
advice of counsel in respect of, any rights with respect to, or collecting, any
or all of the Obligations and/or enforcing any rights with respect to, or
collecting against, Guarantor under this Guaranty.

      (c) No payment or payments made by any Seller, Guarantor, any other
guarantor or any other Person or received or collected by Buyer from any Seller,
Guarantor, any other guarantor or any other Person by virtue of any action or
proceeding or any set-off or appropriation or application at any time or from
time to time in reduction of or in payment of the Obligations shall be deemed to
modify, reduce, release or otherwise affect the liability of Guarantor hereunder
which shall, notwithstanding any such payment or payments other than payments
made by Guarantor in respect of the Obligations or payments received or
collected from Guarantor in respect of the Obligations, remain liable for the
Obligations up to the maximum liability of Guarantor hereunder until the
Obligations are paid in full and the Repurchase Agreement is terminated.

      (d) Guarantor agrees that whenever, at any time, or from time to time, it
shall make any payment to Buyer on account of its liability hereunder, it will
notify Buyer in writing that such payment is made under this Guaranty for such
purpose.

      3. Right of Set-off. Upon the occurrence of any Event of Default,
Guarantor hereby irrevocably authorizes Buyer at any time and from time to time
without notice to Guarantor, any such notice being expressly waived by
Guarantor, to set-off and appropriate and apply any and all deposits (general or
special, time or demand, provisional or final), in any currency, and any other
credits, indebtedness or claims, in any currency, in each case whether direct or
indirect, absolute or contingent, matured or unmatured, at any time held or
owing by Buyer to or for the credit or the account of Guarantor, or any part
thereof in such amounts as Buyer may elect, against and on account of the
obligations and liabilities of Guarantor to Buyer hereunder and claims of every
nature and description of Buyer against Guarantor, in any currency, whether
arising hereunder, under the Repurchase Agreement, any promissory note, or
otherwise, as Buyer may elect, whether or not Buyer has made any demand for
payment and although such obligations, liabilities and claims may be contingent
or unmatured. Buyer shall notify Guarantor promptly of any such set-off and the
application made by Buyer, provided that the failure to give such notice shall
not affect the validity of such set-off and application. The rights of Buyer
under this Section are in addition to other rights and remedies (including,
without limitation, other rights of set-off) which Buyer may have.

      4. No Subrogation. Notwithstanding any payment or payments made by
Guarantor hereunder or any set-off or application of funds of Guarantor by
Buyer, Guarantor shall not be entitled to be subrogated to any of the rights of
Buyer against any Seller or any other guarantor or any collateral security or
guarantee or right of offset held by Buyer for the payment of the Obligations,
nor shall Guarantor seek or be entitled to seek any contribution or
reimbursement from any Seller or any other guarantor in respect of payments made
by Guarantor hereunder, until all amounts owing to Buyer by each Seller on
account of the Obligations are paid in full and the Repurchase Agreement is
terminated. Guarantor hereby subordinates all of its subrogation rights against
each Seller to the full payment of Obligations due Buyer under the Repurchase
Agreement for a period of 91 days following the final payment of the last of all
of the Obligations under the Facility Documents. If any amount shall be paid to
Guarantor on account of such subrogation rights at any time when all of the
Obligations shall not have


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been paid in full, such amount shall be held by Guarantor in trust for Buyer,
segregated from other funds of Guarantor, and shall, forthwith upon receipt by
Guarantor, be turned over to Buyer in the exact form received by Guarantor (duly
indorsed by Guarantor to Buyer, if required), to be applied against the
Obligations, whether matured or unmatured, in such order as Buyer may determine.

      5. Amendments, Etc. with Respect to the Obligations; Waiver of Rights.
Guarantor shall remain obligated hereunder notwithstanding that, without any
reservation of rights against Guarantor and without notice to or further assent
by Guarantor, any demand for payment of any of the Obligations made by Buyer may
be rescinded by Buyer and any of the Obligations continued, and the Obligations,
or the liability of any other party upon or for any part thereof, or any
collateral security or guarantee therefor or right of offset with respect
thereto, may, from time to time, in whole or in part, be renewed, extended,
amended, modified, accelerated, compromised, waived, surrendered or released by
Buyer, and the Facility Documents may be amended, modified, supplemented or
terminated, in whole or in part, as Buyer may deem advisable from time to time,
and any collateral security, guarantee or right of offset at any time held by
Buyer for the payment of the Obligations may be sold, exchanged, waived,
surrendered or released. Buyer shall not have any obligation to protect, secure,
perfect or insure any lien at any time held by it as security for the
Obligations or for this Guaranty or any property subject thereto. When making
any demand hereunder against Guarantor, Buyer may, but shall be under no
obligation to, make a similar demand on Sellers or any other guarantor, and any
failure by Buyer to make any such demand or to collect any payments from Sellers
or any such other guarantor or any release of Sellers or such other guarantor
shall not relieve Guarantor of its obligations or liabilities hereunder, and
shall not impair or affect the rights and remedies, express or implied, or as a
matter of law, of Buyer against Guarantor. For the purposes hereof "demand"
shall include the commencement and continuance of any legal proceedings.

      6. Guaranty Absolute and Unconditional.

      (a) Guarantor waives any and all notice of the creation, renewal,
extension or accrual of any of the Obligations and notice of or proof of
reliance by Buyer upon this Guaranty or acceptance of this Guaranty, the
Obligations, and any of them, shall conclusively be deemed to have been created,
contracted or incurred, or renewed, extended, amended or waived, in reliance
upon this Guaranty; and all dealings between each Seller and Guarantor, on the
one hand, and Buyer, on the other hand, likewise shall be conclusively presumed
to have been had or consummated in reliance upon this Guaranty.

      (b) Guarantor hereby expressly waives all set-offs and counterclaims and
all diligence, presentments, demands for payment, demands for performance,
notices of nonperformance, protests, notices of protest, notices of dishonor,
notices of acceptance of this Guaranty, notices of sale, notice of default or
nonpayment to or upon each Seller or Guarantor, surrender or other handling or
disposition of assets subject to the Repurchase Agreement, any requirement that
Buyer exhaust any right, power or remedy or take any action against Sellers or
against any assets subject to the Repurchase Agreement, and other formalities of
any kind.

      (c) Guarantor understands and agrees that this Guaranty shall be construed
as a continuing, absolute and unconditional guarantee of payment without regard
to (i) the validity, regularity or enforceability of the Repurchase Agreement,
any of the Obligations or any other collateral security therefor or guarantee or
right of offset with respect thereto at any time or from time to time held by
Buyer, (ii) any defense, set-off or counterclaim (other than a defense of
payment or performance) which may at any time be available to or be asserted by
Sellers against Buyer, or (iii) any other circumstance whatsoever (with or
without notice to or knowledge of Sellers or Guarantor) which constitutes, or
might be construed to constitute, an equitable or legal discharge of any Seller
from its Obligations, or of Guarantor from this Guaranty, in bankruptcy or in
any other instance.


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      (d) When pursuing its rights and remedies hereunder against Guarantor,
Buyer may, but shall be under no obligation to, pursue such rights and remedies
as it may have against Sellers or any other Person or against any collateral
security or guarantee for the Obligations or any right of offset with respect
thereto, and any failure by Buyer to pursue such other rights or remedies or to
collect any payments from Sellers or any such other Person or to realize upon
any such collateral security or guarantee or to exercise any such right of
offset, or any release of Sellers or any such other Person or any such
collateral security, guarantee or right of offset, shall not relieve Guarantor
of any liability hereunder, and shall not impair or affect the rights and
remedies, whether express, implied or available as a matter of law, of Buyer
against Guarantor.

      (e) This Guaranty shall remain in full force and effect and be binding in
accordance with and to the extent of its terms upon Guarantor and the successors
and assigns thereof, and shall inure to the benefit of Buyer, and its
successors, indorsees, transferees and assigns, until all the Obligations and
the obligations of Guarantor under this Guaranty shall have been satisfied by
payment in full and the Repurchase Agreement shall be terminated,
notwithstanding that from time to time prior thereto any Seller may be free from
any Obligations.

      (f) Guarantor waives, to the fullest extent permitted by applicable law,
all defenses of surety to which it may be entitled by statute or otherwise.

      7. Reinstatement. The obligations of Guarantor under this Guaranty, and
this Guaranty, shall continue to be effective, or be reinstated, as the case may
be, and be continued in full force and effect, if at any time any payment, or
any part thereof, of any of the Obligations is rescinded, invalidated, declared
fraudulent or preferentially set aside or must otherwise be restored, returned
or repaid by Buyer upon the insolvency, bankruptcy, dissolution, liquidation or
reorganization of any Seller or Guarantor, or upon or as a result of the
appointment of a receiver, intervenor or conservator of, or trustee or similar
officer for, any Seller or Guarantor or any substantial part of its or their
property, or for any other reason, all as though such payments had not been
made.

      8. Payments. Guarantor hereby guarantees that payments hereunder will be
paid to Buyer without set-off or counterclaim in U.S. Dollars.

      9. Event of Default. If an Event of Default shall have occurred and be
continuing, Guarantor agrees that, as between Guarantor and Buyer, the
Obligations may be declared to be due for purposes of this Guaranty
notwithstanding any stay, injunction or other prohibition which may prevent,
delay or vitiate any such declaration as against any Seller and that, in the
event of any such declaration (or attempted declaration), such Obligations shall
forthwith become due by Guarantor for purposes of this Guaranty.

      10. Representations and Warranties; Covenants.

      (a) Guarantor represents and warrants that (i) it is duly authorized to
execute and deliver this Guaranty, to perform its obligations hereunder and has
taken all necessary action to authorize such execution, delivery and
performance; (ii) the person signing this Guaranty on its behalf is duly
authorized to do so on its behalf; (iii) this Guaranty is a legal, valid and
binding obligation of it, enforceable against it in accordance with its terms,
subject to applicable bankruptcy, insolvency, or similar debtor/creditor laws
and general principles of equity and public policy, (iv) no approval, consent or
authorization of this Guaranty from any federal, state, or local regulatory
authority having jurisdiction over it is required or, if required, such
approval, consent or authorization has been or will be obtained, prior to the
initial Transaction; (v) the execution, delivery, and performance of this
Guaranty will not violate any law, regulation, order, judgment, decree,
ordinance, charter, by law, or rule applicable to it or its property or


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constitute a default (or an event which, with notice or lapse of time, or both
would constitute a default) under or result in a breach of any material
agreement or other material instrument by which it is bound or by which any of
its assets are affected; (vi) it has received approval and authorization to
enter into this Guaranty pursuant to its internal policies and procedures; (vii)
this Guaranty is not entered into in contemplation of insolvency or with intent
to hinder, delay or defraud any creditor; and (viii) it has examined and
comprehends the Facility Documents in their entirety.

      (b) Guarantor represents, warrants and covenants to Buyer that as of the
date of this Guaranty and as of the date of any Transaction under the Repurchase
Agreement and at all times while this Guaranty and any Transaction under the
Repurchase Agreement are in effect or there are Obligations outstanding:

            (i) Performance of Guaranty. Guarantor does not believe, nor does it
      have any reason or cause to believe, that it cannot perform each and every
      covenant contained in this Guaranty on its part to be performed;

            (ii) Guarantor Not Insolvent. Guarantor is not, and with the passage
      of time does not expect to become, insolvent and is not contemplating the
      commencement of any isolvency; and

            (iii) Ownership of Seller. Guarantor is now, and will remain, the
      direct or indirect owner of all of the capital stock and other beneficial
      interests in each Seller.

      (c) Guarantor covenants and agrees that it shall not consolidate with or
merge into, or transfer all or substantially all of its assets to, another
entity (or permit the occurrence of same) unless the resulting surviving or
transferee entity (i) is a corporation organized under the laws of the United
States of America or political subdivision thereof; (ii) assumes all the
obligations of Guarantor under this Agreement pursuant to an agreement
reasonably satisfactory to Buyer or by law; (iii) such merger, consolidation or
asset transfer has received the prior written approval of the regulatory
authorities having jurisdiction over such transaction; and (iv) Buyer receives
as part of the aforementioned agreement assurances from such entity prior to the
proposed merger, consolidation or asset acquisition, reasonably satisfactory to
Buyer, that such entity would not, following such proposed transaction, present
an unacceptable credit risk to Buyer and would be an entity able to faithfully
perform under the terms of this Guaranty.

      11. Notices. All notices, requests and other communications provided for
herein (including without limitation any modifications of, or waivers, requests
or consents under, this Guaranty) shall be given or made in writing (including
without limitation by telex or telecopy) delivered to the intended recipient at
the "Address for Notices" specified below its name on the signature pages of the
Repurchase Agreement, or, with respect to Guarantor, at the "Address for
Notices" specified below its name on the signature page hereof); or, as to any
party, at such other address as shall be designated by such party in a written
notice to each other party. All such communications shall be deemed to have been
duly given when transmitted by telex or telecopy or personally delivered or, in
the case of a mailed notice, upon receipt, in each case given or addressed as
aforesaid.

      12. Severability. Any provision of this Guaranty which is prohibited or
unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective
to the extent of such prohibition or unenforceability without invalidating the
remaining provisions hereof, and any such prohibition or unenforceability in any
jurisdiction shall not invalidate or render unenforceable such provision in any
other jurisdiction.


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      13. Integration. This Guaranty represents the agreement of Guarantor with
respect to the subject matter hereof and thereof and there are no promises or
representations by Buyer relative to the subject matter hereof or thereof not
reflected herein or therein.

      14. Amendments in Writing; No Waiver; Cumulative Remedies.

      (a) None of the terms or provisions of this Guaranty may be waived,
amended, supplemented or otherwise modified except by a written instrument
executed by Guarantor and Buyer, provided that any provision of this Guaranty
may be waived by Buyer.

      (b) Buyer shall not by any act (except by a written instrument pursuant to
Section 14(a) hereof), delay, indulgence, omission or otherwise be deemed to
have waived any right or remedy hereunder or to have acquiesced in any Default
or in any breach of any of the terms and conditions hereof. No failure to
exercise, nor any delay in exercising, on the part of Buyer, any right, power or
privilege hereunder shall operate as a waiver thereof. No single or partial
exercise of any right, power or privilege hereunder shall preclude any other or
further exercise thereof or the exercise of any other right, power or privilege.
A waiver by Buyer of any right or remedy hereunder on any one occasion shall not
be construed as a bar to any right or remedy which Buyer would otherwise have on
any future occasion.

      (c) The rights and remedies herein provided are cumulative, may be
exercised singly or concurrently and are not exclusive of any other rights or
remedies provided by law.

      15. Section Headings. The section headings used in this Guaranty are for
convenience of reference only and are not to affect the construction hereof or
be taken into consideration in the interpretation hereof.

      16. Successors and Assigns. This Guaranty shall be binding upon the
successors and assigns of Guarantor and shall inure to the benefit of Buyer and
its successors and assigns. This Guaranty may not be assigned by Guarantor
without the express written consent of Buyer. Buyer may from time to time assign
all or a portion of its rights and obligations under this Guaranty; provided
that if such assignment is to a Person that is not an Affiliate of Buyer and no
Default shall have occurred and be continuing, any such assignment shall be
subject to the prior written consent of Guarantor, which consent shall not be
unreasonably withheld, delayed or conditioned.

      17. Governing Law. This Guaranty shall be governed by New York law without
reference to its choice of law doctrine.

      18. SUBMISSION TO JURISDICTION; WAIVERS. GUARANTOR HEREBY IRREVOCABLY AND
UNCONDITIONALLY:

            (A) SUBMITS FOR ITSELF AND ITS PROPERTY IN ANY LEGAL ACTION OR
      PROCEEDING RELATING TO THIS GUARANTY AND THE OTHER FACILITY DOCUMENTS, OR
      FOR RECOGNITION AND ENFORCEMENT OF ANY JUDGMENT IN RESPECT THEREOF, TO THE
      NON-EXCLUSIVE GENERAL JURISDICTION OF THE COURTS OF THE STATE OF NEW YORK,
      THE FEDERAL COURTS OF THE UNITED STATES OF AMERICA FOR THE SOUTHERN
      DISTRICT OF NEW YORK, AND APPELLATE COURTS FROM ANY THEREOF;

            (B) CONSENTS THAT ANY SUCH ACTION OR PROCEEDING MAY BE BROUGHT IN
      SUCH COURTS AND, TO THE EXTENT PERMITTED BY LAW, WAIVES ANY OBJECTION THAT
      IT MAY NOW OR HEREAFTER HAVE TO THE


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      VENUE OF ANY SUCH ACTION OR PROCEEDING IN ANY SUCH COURT OR THAT SUCH
      ACTION OR PROCEEDING WAS BROUGHT IN AN INCONVENIENT COURT AND AGREES NOT
      TO PLEAD OR CLAIM THE SAME;

            (C) AGREES THAT SERVICE OF PROCESS IN ANY SUCH ACTION OR PROCEEDING
      MAY BE EFFECTED BY MAILING A COPY THEREOF BY REGISTERED OR CERTIFIED MAIL
      (OR ANY SUBSTANTIALLY SIMILAR FORM OF MAIL), POSTAGE PREPAID, TO ITS
      ADDRESS SET FORTH UNDER ITS SIGNATURE BELOW OR AT SUCH OTHER ADDRESS OF
      WHICH BUYER SHALL HAVE BEEN NOTIFIED; AND

            (D) AGREES THAT NOTHING HEREIN SHALL AFFECT THE RIGHT TO EFFECT
      SERVICE OF PROCESS IN ANY OTHER MANNER PERMITTED BY LAW OR SHALL LIMIT THE
      RIGHT TO SUE IN ANY OTHER JURISDICTION.

      19. WAIVER OF JURY TRIAL. EACH OF GUARANTOR AND BUYER HEREBY IRREVOCABLY
WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO
TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS
GUARANTY, ANY OTHER REPURCHASE DOCUMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY
OR THEREBY.

                            [SIGNATURE PAGE FOLLOWS]



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      IN WITNESS WHEREOF, Guarantor has caused this Guaranty to be duly executed
and delivered by its duly authorized officer as of the day and year first above
written.


GUARANTOR:                                   Address for Notices to Guarantor:

AMERICAN HOME MORTGAGE INVESTMENT CORP.,     American Home Mortgage Investment
a Maryland corporation                       Corp.
                                             538 Broadhollow Road
                                             Melville, New York 11747
                                             Attention: Alan B. Horn
                                             Facsimile No.: 800-209-7276
By:  /s/ Stephen A. Hozie                    Telephone No.: 516-396-7703
    -----------------------------
Name: Stephen A. Hozie
Title: Executive Vice President and Chief
Financial Officer


                      SIGNATURE PAGE TO GUARANTY AGREEMENT