|   |  x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 |
|--------|---------|--------------------------------------------------------------------------------------|

|   |  o | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 |
|--------|---------|-----------------------------------------------------------------------------------------------|

|   |  Commission File Number of issuing entity:  001-33605              |   |
|--------|-----------------------------------------------------------------------------------|--------|
|   |                                                                              |   |
|   |   STRATS(SM) Trust for AMBAC Financial Group, Inc. Securities, Series 2007-1 |   |
|   |  (Exact name of issuing entity as specified in its charter)                  |   |
|   |                                                                              |   |
|   |   Commission File Number of depositor and sponsor: 001-31818                 |   |
|   |                                                                              |   |
|   |  Synthetic Fixed-Income Securities, Inc.                                     |   |
|   |  (Exact name of depositor and sponsor as specified in its charter)           |   |
|   |                                                                              |   |
|   |                                                                              |   |

| New York                                                      | 20-7474289                           |
|---------------------------------------------------------------|--------------------------------------|
| (State or other jurisdiction of incorporationor organization) | (I.R.S. Employer Identification No.) |
|                                                          |                                 |
|                                                          |                                 |
| 301 South College Street, Charlotte, North Carolina           | 28288                                |
| (Address of principal executive offices)                      | (Zip Code)                           |
|                                                          |                                 |

----

|  Yes  |  o |   No |  x |
|-----------------|---------|----------------|---------|

|  Yes  |  o |   No |  x |
|-----------------|---------|----------------|---------|

|  Yes  |  x |   No |  o |
|-----------------|---------|----------------|---------|

|  Yes  |  x |   No |  o |
|-----------------|---------|----------------|---------|

|  Large accelerated filer |  o |  Accelerated filer |  o |  Non- accelerated filer |  x |  Smaller reporting company |  o |
|-------------------------------|---------|-------------------------|---------|------------------------------|---------|---------------------------------|---------|

|  Yes  |  o |   No |  x |
|-----------------|---------|----------------|---------|

----

----

----

| Item 1112(b) of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | Significant Obligors of Pool Assets (Financial Information).                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|
| The primary asset of the issuing entity is the underlying securities, $37,500,000 of 6.15% DISCS due February 15, 2037 issued by AMBAC Financial Group, Inc. The issuer of the underlying securities, therefore, may be considered a significant obligor. The issuer of the underlying securities is subject to the information reporting requirements of the Securities Exchange Act of 1934 (the “Exchange Act”). For information on the issuer of the underlying securities please see its periodic and current reports filed with the Securities and Exchange Commission (the “Commission”) under its Exchange Act file number, 001-10777.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Item 1114(b)(2) of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            | Credit Enhancement and Other Support, Except for Certain DerivativesInstruments (Information Regarding Significant EnhancementProviders Financial Information). |
| Based on the standards set forth in Item 1114(b)(2) of Regulation AB, no information is required in response to this Item.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Item 1115(b) of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          | Certain Derivatives Instruments (Financial Information).                                                                                                        |
| Based on the standards set forth in Item 1115(b) of Regulation AB, no information is required in response to this Item.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Item 1117 of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | Legal Proceedings.                                                                                                                                              |
| There are no legal proceedings pending, or any proceedings known to be contemplated, by governmental authorities against the depositor, the Trustee or the issuing entity, or any property thereof, that is material to the holders of the Certificates.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Item 1119 of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | Affiliations and Certain Relationships and Related Transactions.                                                                                                |
| Based on the standards set forth in Item 1119 of Regulation AB, no information is required in response to this Item.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Item 1122 of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | Compliance with Applicable Servicing Criteria                                                                                                                   |
| U.S. Bank Trust National Association has been identified by the registrant as a party participating in the servicing function with respect to the pool assets held by STRATS(SM) Trust for AMBAC Financial Group, Inc. Securities, Series 2007-1.  U.S. Bank Trust National Association has completed a report on an assessment of compliance with the servicing criteria applicable (the “Report on Assessment”) as of March [  ], 2012 and for a period beginning January 1, 2011 through and including December 31, 2011, which Report on Assessment is attached as an exhibit to this Form 10-K. In addition, U.S. Bank Trust National Association has provided an attestation report (the “Attestation Report”) by a registered independent public accounting firm regarding its related Report on Assessment. The Attestation Report is attached as an exhibit to this Form 10-K. Neither the Report on Assessment or the related Attestation Report has identified any material instances of noncompliance with the servicing criteria described in the Report on Assessment as being applicable to U.S. Bank Trust National Association. |
| Item 1123 of Regulation AB.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | Servicer Compliance Statement.                                                                                                                                  |
| U.S. Bank Trust National Association has provided a statement of compliance (the “Compliance Statement”) for the period from and including January 1, 2011 through and including December 31, 2011, which has been signed by an authorized officer of U.S. Bank Trust National Association. The Compliance Statement of U.S. Bank Trust National Association is attached as an exhibit to this Form 10-K.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |

----

|   | 1. | None. |
|--------|----|-------|

|   | 2. | None. |
|--------|----|-------|

|   | 3. | Exhibits: |
|--------|----|-----------|

|   | 31.1 – Certification by Director of the Registrant pursuant to 15 U.S.C. Section 7241, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. |
|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 33.1 – Report on Assessment of Compliance with Servicing Criteria for U.S. Bank Trust National Association for the period from and including January 1, 2011 through and including December 31, 2011. |
|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 34.1 – Attestation Report of Ernst & Young LLP on Assessment of Compliance with Servicing Criteria relating to U.S. Bank Trust National Association. |
|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | 35.1 – Servicer Compliance Statement of U.S. Bank Trust National Association for the period from and including January 1, 2011 through and including December 31, 2011. |
|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

----

|   | Synthetic Fixed-Income Securities, Inc.,                                                                                                                                                    |
|--------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   | as Depositor for the Trust                                                                                                                                                                  |
|   |                                                                                                                                                                                        |
|   |                                                                                                                                                                                        |
|   | By:    /s/ William Threadgill                        |
|   | Name:  William Threadgill                                                                                                                                                         |
|   | Title:    President                                                                                                                                                     |
|   |                                                                                                                                                                                        |
|   | (senior officer in charge of the securitizations of thedepositor)                                                                                                                           |

----

| Exhibit Number in thisForm 10-K | Description of Exhibits                                                                                                                                                                        |
|--------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 31.1                                 | Certification by Director of the Registrant pursuant to 15 U.S.C. Section 7241, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.                                |
| 33.1                                 | Report on Assessment of Compliance with Servicing Criteria for U.S. Bank Trust National Association for the period from and including January 1, 2011 through and including December 31, 2011. |
| 34.1                                 | Attestation Report of Ernst & Young LLP on Assessment of Compliance with Servicing Criteria relating to U.S. Bank Trust National Association.                                              |
| 35.1                                 | Servicer Compliance Statement of U.S. Bank Trust National Association for the period from and including January 1, 2011 through and including December 31, 2011.                               |