# EDGAR Filing Document

**Accession Number:** 0000063075
**File Stem:** 0001752724-25-152202
**Filing Date:** 2025-6
**Character Count:** 55754
**Document Hash:** 5501a9a30239d0086030f7bd825b9593
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001752724-25-152202.hdr.sgml**: 20250624

**ACCESSION NUMBER**: 0001752724-25-152202

**CONFORMED SUBMISSION TYPE**: NPORT-P

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250430

**FILED AS OF DATE**: 20250624

**DATE AS OF CHANGE**: 20250624

**PERIOD START**: 20251031

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MFS SERIES TRUST IX
- **CENTRAL INDEX KEY:** 0000063075

**ORGANIZATION NAME:**
- **EIN:** 042535629
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0430

**FILING VALUES:**
- **FORM TYPE:** NPORT-P
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-02464
- **FILM NUMBER:** 251066833

**BUSINESS ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **STREET 2:** 21ST FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199
- **BUSINESS PHONE:** 18006372929

**MAIL ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **STREET 2:** 21ST FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS SERIES TRUST IX /MA/
- **DATE OF NAME CHANGE:** 19951218

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS SERIES TRUST IX
- **DATE OF NAME CHANGE:** 19950207

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS BOND FUND
- **DATE OF NAME CHANGE:** 19930408

## Series and Classes Contracts Data

### MFS Inflation-Adjusted Bond Fund (Series ID: S000002493)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000006724 | A            | MIAAX           |
| C000006725 | R4           | MIAJX           |
| C000006726 | B            | MIABX           |
| C000006727 | C            | MIACX           |
| C000006728 | I            | MIAIX           |
| C000006730 | R1           | MIALX           |
| C000006732 | R2           | MIATX           |
| C000006733 | R3           | MIAHX           |
| C000126364 | R6           | MIAKX           |

## Form NPORT-P: Monthly Portfolio Investments Report

### NPORT-P: Part A: General Information

**Item A.1. Information about the Registrant.**

- **a. Name of Registrant:** MFS SERIES TRUST IX

- **b. Investment Company Act file number:** 811-02464

- **c. CIK number of Registrant:** 0000063075

- **d. LEI of Registrant:** 549300IJONSVWD5I9F62

- **e. Address and telephone number of Registrant.**

  - **Street Address 1:** 111 HUNTINGTON AVENUE

  - **City:** BOSTON

  - **State:** MA

  - **Foreign country:** US

  - **Zip / Postal Code:** 02199

  - **Telephone number:** 617-954-5000

**Item A.2. Information about the Series.**

- **a. Name of Series:** MFS Inflation-Adjusted Bond Fund

- **b. EDGAR series identifier (if any):** S000002493

- **c. LEI of Series:** VOHO802M9IKG3IZTEN75

**Item A.3. Reporting period.**

- **a. Date of fiscal year-end:** 2025-10-31

- **b. Date as of which information is reported:** 2025-04-30

**Item A.4. Final filing**

Does the Fund anticipate that this will be its final filing on Form N-PORT? **No**

### Fund Information

**Total Assets:** $1446078541.33

**Total Liabilities:** $373625.97

**Net Assets:** $1445704915.36

**Currency Risk Metrics (dv01):**

- 

**Credit Spread Risk - Investment Grade (dv01):**

- **3-Month:** -498.11000000 | **1-Year:** -3650.76000000 | **5-Year:** -4059.09000000 | **10-Year:** -133.81000000 | **30-Year:** 0.00000000

**Credit Spread Risk - Non-Investment Grade (dv01):**

- **3-Month:** -130.84000000 | **1-Year:** -2888.53000000 | **5-Year:** -5751.87000000 | **10-Year:** -1533.95000000 | **30-Year:** -498.65000000

**Monthly Return Information**

| Class               | Month 1 Return (%)   | Month 2 Return (%)   | Month 3 Return (%)   |
|:---|:---|:---|:---|
| Class ID C000006724 | 2.23%                | 0.67%                | -0.11%               |
| Class ID C000006725 | 2.12%                | 0.70%                | 0.00%                |
| Class ID C000126364 | 2.11%                | 0.72%                | 0.00%                |
| Class ID C000006733 | 2.12%                | 0.76%                | -0.11%               |
| Class ID C000006728 | 2.23%                | 0.72%                | 0.00%                |
| Class ID C000006726 | 2.02%                | 0.67%                | -0.11%               |
| Class ID C000006732 | 2.13%                | 0.71%                | -0.11%               |
| Class ID C000006730 | 2.03%                | 0.73%                | -0.22%               |
| Class ID C000006727 | 2.02%                | 0.72%                | -0.22%               |

**Monthly Gains & Losses**

| Period   | Net Realized Gain/Loss   | Net Unrealized Appreciation/Depreciation   |
|:---|:---|:---|
| Month 1  | $-3711805.51             | $34635843.88                               |
| Month 2  | $436134.54               | $-2177114.04                               |
| Month 3  | $-8622282.85             | $-2577470.29                               |

**Designated Index Information**

- **Index Name:** BBG US Treasury Infl Prot Sec Idx

- **Index Identifier:** LBUTTRUU

### Schedule of Portfolio Investments

| Name                                             | Title                                                                                                                                  | Identifiers                                   | Payoff Profile   | Asset Category   | Issuer Category   | Country   |   Balance | Units   | Value (USD)   | % of Net Assets   | Maturity Date   | Coupon Type   | Annualized Rate (%)   | Restricted?   |   Fair Value Level | Lending Status   |
|:---|:---|:---|:---|:---|:---|:---|---:|:---|:---|:---|:---|:---|:---|:---|---:|:---|
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F9ZC8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  11388256 | PA      | $447115.46    | 0.03%             | 2031-01-25      | Variable      | 0.87%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810TE8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  46829227 | PA      | $25273669.00  | 1.75%             | 2052-02-15      | Fixed         | 0.13%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | FREMF 2025-K169 Mortgage Trust                                                                                                         | CUSIP: 3137HK2F0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  35704535 | PA      | $867805.86    | 0.06%             | 2035-01-25      | Variable      | 0.43%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                       | Fannie Mae REMICS                                                                                                                      | CUSIP: 3136BBTT9<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   2248000 | PA      | $436899.94    | 0.03%             | 2050-09-25      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| Michigan Finance Authority                       | Michigan Finance Authority Student Loan Asset-Backed Notes 2021-1                                                                      | CUSIP: 59447TV83<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    726802 | PA      | $721724.92    | 0.05%             | 2061-07-25      | Fixed         | 1.30%                 | No            |                  2 | On Loan: No      |
| Tobacco Settlement Finance Authority             | TOBACCO SETTLEMENT FIN AUTH WV ASSET BACKED                                                                                            | CUSIP: 88880LAG8<br>LEI: N/A                  | Long             | DBT              | MUN               | US        |    835000 | PA      | $833009.03    | 0.06%             | 2025-06-01      | Fixed         | 1.65%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                       | Fannie Mae REMICS                                                                                                                      | CUSIP: 3136BR3E5<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   3614091 | PA      | $3616154.75   | 0.25%             | 2054-06-25      | Floating      | 5.50%                 | No            |                  2 | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B24 Mortgage Trust                                                                                                      | CUSIP: 08163CBE8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  15366416 | PA      | $676434.25    | 0.05%             | 2054-03-15      | Variable      | 1.25%                 | No            |                  2 | On Loan: No      |
| LCH Ltd.                                         | Long: BM11746   IRS USD R V 12MUSCPI SM11746_FLO CCPINFLATIONZERO / Short: BM11746   IRS USD P F  2.75500 SM11746_FIX CCPINFLATIONZERO | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |  80400000 | OU      | $496933.91    | 0.03%             |  |  |  | No            |                  2 | On Loan: No      |
| AREIT CRE Trust                                  | AREIT 2022-CRE6 Trust                                                                                                                  | CUSIP: 04002VAC5<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   2462500 | PA      | $2447421.87   | 0.17%             | 2037-01-20      | Floating      | 6.00%                 | Yes           |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CJY8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  82915760 | PA      | $82107156.72  | 5.68%             | 2034-01-15      | Fixed         | 1.75%                 | No            |                  2 | On Loan: No      |
| Barclays Commercial Mortgage Securities LLC      | BBCMS Trust 2021-C10                                                                                                                   | CUSIP: 05551VBK8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  12331332 | PA      | $670887.37    | 0.05%             | 2054-07-15      | Variable      | 1.33%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CGK1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  75896489 | PA      | $72320495.08  | 5.00%             | 2033-01-15      | Fixed         | 1.13%                 | No            |                  2 | On Loan: No      |
| AmeriCredit Automobile Receivables Trust         | AmeriCredit Automobile Receivables Trust 2024-1                                                                                        | CUSIP: 023947AC8<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   2632459 | PA      | $2630645.81   | 0.18%             | 2028-02-18      | Floating      | 4.95%                 | No            |                  2 | On Loan: No      |
| LAD Auto Receivables Trust                       | LAD Auto Receivables Trust 2025-1                                                                                                      | CUSIP: 505712AB5<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   2216000 | PA      | $2214247.37   | 0.15%             | 2027-12-15      | Fixed         | 4.60%                 | Yes           |                  2 | On Loan: No      |
| Michigan Finance Authority                       | MICHIGAN ST FIN AUTH REVENUE                                                                                                           | CUSIP: 59447TH89<br>LEI: 54930022O46HOX5J1D14 | Long             | DBT              | MUN               | US        |     42597 | PA      | $42190.26     | 0.00%             | 2030-06-01      | Fixed         | 2.33%                 | No            |                  2 | On Loan: No      |
| Enterprise Fleet Financing LLC                   | Enterprise Fleet Financing 2025-1 LLC                                                                                                  | CUSIP: 29390HAB5<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    906000 | PA      | $907604.71    | 0.06%             | 2027-10-20      | Fixed         | 4.65%                 | Yes           |                  2 | On Loan: No      |
| Santander Drive Auto Receivables Trust           | Santander Drive Auto Receivables Trust 2025-1                                                                                          | CUSIP: 80288DAB2<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   4609202 | PA      | $4609325.93   | 0.32%             | 2027-08-16      | Fixed         | 4.76%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FXZ50<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  29623093 | PA      | $428178.11    | 0.03%             | 2031-01-25      | Variable      | 0.41%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38383KU42<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   1788311 | PA      | $1785045.44   | 0.12%             | 2074-08-20      | Floating      | 5.00%                 | No            |                  2 | On Loan: No      |
| Barclays Commercial Mortgage Securities LLC      | BBCMS Mortgage Trust 2021-C9                                                                                                           | CUSIP: 05493EAZ5<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |   7892317 | PA      | $550701.41    | 0.04%             | 2054-02-15      | Variable      | 1.70%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38380LCL5<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   3762424 | PA      | $3782101.61   | 0.26%             | 2068-05-20      | Floating      | 5.86%                 | No            |                  2 | On Loan: No      |
| Fanniemae-Aces                                   | Fannie Mae-Aces                                                                                                                        | CUSIP: 3136BTGM9<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   3914761 | PA      | $3830802.69   | 0.26%             | 2027-07-25      | Variable      | 3.00%                 | No            |                  2 | On Loan: No      |
| Palmer Square Loan Funding Ltd                   | Palmer Square Loan Funding 2025-1 Ltd                                                                                                  | CUSIP: 69704CAA5<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   4500000 | PA      | $4467838.50   | 0.31%             | 2033-02-15      | Floating      | 5.12%                 | Yes           |                  2 | On Loan: No      |
| GREAT AMERICA LEASING RECEIVABLES                | GreatAmerica Leasing Receivables Funding LLC                                                                                           | CUSIP: 39154GAH9<br>LEI: 549300JFP7GIDD4UWO79 | Long             | ABS-O            | CORP              | US        |   2485000 | PA      | $2487380.63   | 0.17%             | 2027-10-15      | Fixed         | 4.52%                 | Yes           |                  2 | On Loan: No      |
| Wells Fargo Commercial Mortgage Trust            | Wells Fargo Commercial Mortgage Trust 2021-C60                                                                                         | CUSIP: 95003DBP2<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |   9239477 | PA      | $623798.69    | 0.04%             | 2054-08-15      | Variable      | 1.62%                 | No            |                  2 | On Loan: No      |
| LAD Auto Receivables Trust                       | LAD Auto Receivables Trust 2024-3                                                                                                      | CUSIP: 505709AB1<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1575200 | PA      | $1574713.98   | 0.11%             | 2027-11-15      | Fixed         | 4.64%                 | Yes           |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HAAL0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  29100000 | PA      | $625076.73    | 0.04%             | 2033-05-25      | Variable      | 0.43%                 | No            |                  2 | On Loan: No      |
| Colorado Health Facilities Authority             | COLORADO ST HLTH FACS AUTH REVENUE                                                                                                     | CUSIP: 19648FRX4<br>LEI: 5493002JB6DRFRZPEQ21 | Long             | DBT              | MUN               | US        |    600000 | PA      | $588108.84    | 0.04%             | 2026-12-01      | Fixed         | 2.80%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810RL4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  61471837 | PA      | $45166356.25  | 3.12%             | 2045-02-15      | Fixed         | 0.75%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H3EZ1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   9783880 | PA      | $449108.47    | 0.03%             | 2031-09-25      | Variable      | 0.95%                 | No            |                  2 | On Loan: No      |
| Bridgecrest Lending Auto Securitization Trust    | Bridgecrest Lending Auto Securitization Trust 2025-1                                                                                   | CUSIP: 10806HAB3<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   2747000 | PA      | $2743865.95   | 0.19%             | 2027-09-15      | Fixed         | 4.71%                 | No            |                  2 | On Loan: No      |
| Kubota Credit Owner Trust                        | Kubota Credit Owner Trust 2025-1                                                                                                       | CUSIP: 50117FAB7<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1780000 | PA      | $1785488.27   | 0.12%             | 2027-12-15      | Fixed         | 4.61%                 | Yes           |                  2 | On Loan: No      |
| Chicago Board of Trade                           | US 10YR NOTE (CBT)JUN25                                                                                                                | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |      -336 | NC      | $-494316.07   | -0.03%            |  |  |  | No            |                  1 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F9Z38<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   8529316 | PA      | $393363.52    | 0.03%             | 2031-01-25      | Variable      | 1.03%                 | No            |                  2 | On Loan: No      |
| Bank                                             | BANK 2021-BNK31                                                                                                                        | CUSIP: 06541ABM1<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  19007088 | PA      | $1093894.02   | 0.08%             | 2054-02-15      | Variable      | 1.39%                 | No            |                  2 | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B23 Mortgage Trust                                                                                                      | CUSIP: 08162RAF4<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  25174663 | PA      | $1306982.93   | 0.09%             | 2054-02-15      | Variable      | 1.36%                 | No            |                  2 | On Loan: No      |
| ARI Fleet Lease Trust                            | ARI Fleet Lease Trust 2025-A                                                                                                           | CUSIP: 04033CAB2<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1437000 | PA      | $1435195.42   | 0.10%             | 2034-01-17      | Fixed         | 4.38%                 | Yes           |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810FD5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  66994655 | PA      | $71928989.32  | 4.98%             | 2028-04-15      | Fixed         | 3.63%                 | No            |                  2 | On Loan: No      |
| M&T Bank Auto Receivables Trust                  | M&T Bank Auto Receivables Trust 2025-1                                                                                                 | CUSIP: 55287XAB1<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1334000 | PA      | $1335201.13   | 0.09%             | 2028-05-15      | Fixed         | 4.63%                 | Yes           |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FNXA3<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   5003724 | PA      | $4998926.78   | 0.35%             | 2029-08-25      | Floating      | 4.97%                 | No            |                  2 | On Loan: No      |
| LCH Ltd.                                         | Long: BM11591   IRS USD R V 12MUSCPI SM11591_FLO CCPINFLATIONZERO / Short: BM11591   IRS USD P F  2.63650 SM11591_FIX CCPINFLATIONZERO | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |  40400000 | OU      | $391885.66    | 0.03%             |  |  |  | No            |                  2 | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38376RS56<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   2133257 | PA      | $2152073.39   | 0.15%             | 2067-01-20      | Floating      | 5.25%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810RA8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  36662833 | PA      | $27419101.08  | 1.90%             | 2043-02-15      | Fixed         | 0.63%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38384LAF6<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   2066972 | PA      | $2065791.93   | 0.14%             | 2075-01-20      | Floating      | 5.00%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FUZZ0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   6326494 | PA      | $469117.12    | 0.03%             | 2030-05-25      | Variable      | 1.77%                 | No            |                  2 | On Loan: No      |
| Dell Equipment Finance Trust                     | Dell Equipment Finance Trust 2023-3                                                                                                    | CUSIP: 24702EAB6<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    121425 | PA      | $121555.70    | 0.01%             | 2029-04-23      | Fixed         | 6.10%                 | Yes           |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FYUL8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  36201255 | PA      | $875205.17    | 0.06%             | 2031-03-25      | Variable      | 0.61%                 | No            |                  2 | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B28 Mortgage Trust                                                                                                      | CUSIP: 08163GAZ3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  25024654 | PA      | $1388547.99   | 0.10%             | 2054-08-15      | Variable      | 1.37%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 912828V49<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  50418577 | PA      | $50077855.99  | 3.46%             | 2027-01-15      | Fixed         | 0.38%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                      | Freddie Mac REMICS                                                                                                                     | CUSIP: 3137HJQL4<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   4407323 | PA      | $4405853.20   | 0.30%             | 2055-02-25      | Floating      | 5.30%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810QV3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 133378026 | PA      | $104168539.61 | 7.21%             | 2042-02-15      | Fixed         | 0.75%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HHJ44<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   7419164 | PA      | $525112.85    | 0.04%             | 2034-09-25      | Variable      | 1.09%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 9128282L3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  88748143 | PA      | $88146985.44  | 6.10%             | 2027-07-15      | Fixed         | 0.38%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H2NA8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   7521262 | PA      | $384243.22    | 0.03%             | 2031-07-25      | Variable      | 1.04%                 | No            |                  2 | On Loan: No      |
| SBNA Auto Lease Trust                            | SBNA Auto Lease Trust 2025-A                                                                                                           | CUSIP: 78437KAB0<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1975000 | PA      | $1975468.47   | 0.14%             | 2027-04-20      | Fixed         | 4.68%                 | Yes           |                  2 | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38384XSB0<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   2080401 | PA      | $2070112.29   | 0.14%             | 2054-10-20      | Floating      | 5.40%                 | No            |                  2 | On Loan: No      |
| Morgan Stanley Capital I Trust                   | Morgan Stanley Capital I Trust 2021-L7                                                                                                 | CUSIP: 61772TBN3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  27241226 | PA      | $1221551.06   | 0.08%             | 2054-10-15      | Variable      | 1.19%                 | No            |                  2 | On Loan: No      |
| Morgan Stanley & Co. LLC                         | Long: SM11576   IRS USD R V 12MUSCPI SM11576_FLO INFLATIONZERO / Short: SM11576   IRS USD P F  2.48200 SM11576_FIX INFLATIONZERO       | CUSIP: 000000000<br>LEI: 9R7GPTSO7KV3UQJZQ078 | N/A              | DIR              |  | US        |  79900000 | OU      | $1113286.65   | 0.08%             |  |  |  | No            |                  2 | On Loan: No      |
| Alinea CLO LTD                                   | Alinea CLO 2018-1 Ltd                                                                                                                  | CUSIP: 016269AE2<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   1715351 | PA      | $1713411.08   | 0.12%             | 2031-07-20      | Floating      | 5.17%                 | Yes           |                  2 | On Loan: No      |
| School District of Philadelphia/The              | PHILADELPHIA PA SCH DIST                                                                                                               | CUSIP: 717883UB6<br>LEI: 254900HSKDHZKBZCUL90 | Long             | DBT              | MUN               | US        |   1925000 | PA      | $2057957.44   | 0.14%             | 2030-09-01      | Fixed         | 6.00%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H4BT6<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  32486236 | PA      | $975594.15    | 0.07%             | 2031-09-25      | Variable      | 0.63%                 | No            |                  2 | On Loan: No      |
| 3650R Commercial Mortgage Trust                  | 3650R 2021-PF1 Commercial Mortgage Trust                                                                                               | CUSIP: 88581EAF8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  14471991 | PA      | $581007.01    | 0.04%             | 2054-11-15      | Variable      | 1.11%                 | No            |                  2 | On Loan: No      |
| MFS Institutional Money Market Portfolio         | MFS Institutional Money Market Portfolio                                                                                               | CUSIP: 55291X109<br>LEI: 5L2W638H85N8T1136O07 | Long             | EC               | RF                | US        |  59339921 | NS      | $59339920.79  | 4.10%             |  |  |  | No            |                  1 | On Loan: No      |
| PFS Financing Corp.                              | PFS Financing Corp                                                                                                                     | CUSIP: 69335PFS9<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   3476000 | PA      | $3464469.07   | 0.24%             | 2029-01-15      | Floating      | 4.99%                 | Yes           |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H13T1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   4421663 | PA      | $276666.99    | 0.02%             | 2031-05-25      | Variable      | 1.32%                 | No            |                  2 | On Loan: No      |
| New Jersey Turnpike Authority                    | NEW JERSEY ST TURNPIKE AUTH TURNPIKE REVENUE                                                                                           | CUSIP: 646140DP5<br>LEI: 5493005YN67D71KSMI84 | Long             | DBT              | MUN               | US        |    745000 | PA      | $729792.39    | 0.05%             | 2026-01-01      | Fixed         | 1.05%                 | No            |                  2 | On Loan: No      |
| Chase Auto Owner Trust                           | Chase Auto Owner Trust 2024-5                                                                                                          | CUSIP: 16144QAB1<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1345159 | PA      | $1343344.60   | 0.09%             | 2027-11-26      | Fixed         | 4.40%                 | Yes           |                  2 | On Loan: No      |
| Fannie Mae                                       | Fannie Mae REMICS                                                                                                                      | CUSIP: 3136BQRD3<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   2130750 | PA      | $2143651.18   | 0.15%             | 2053-11-25      | Floating      | 5.80%                 | No            |                  2 | On Loan: No      |
| HOWARD UNIVERSITY                                | Howard University                                                                                                                      | CUSIP: 442851AG6<br>LEI: 5493000EDHIQDJSTOF89 | Long             | DBT              | CORP              | US        |    402000 | PA      | $396427.78    | 0.03%             | 2025-10-01      | Fixed         | 2.52%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CBF7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 199135345 | PA      | $184065958.98 | 12.73%            | 2031-01-15      | Fixed         | 0.13%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HDJK7<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  26637555 | PA      | $461940.48    | 0.03%             | 2029-05-25      | Variable      | 0.63%                 | No            |                  2 | On Loan: No      |
| American Credit Acceptance Receivables Trust     | American Credit Acceptance Receivables Trust 2024-1                                                                                    | CUSIP: 02531AAA9<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |     24626 | PA      | $24634.92     | 0.00%             | 2027-01-12      | Fixed         | 5.61%                 | Yes           |                  2 | On Loan: No      |
| Morgan Stanley Capital I Trust                   | Morgan Stanley Capital I Trust 2021-L6                                                                                                 | CUSIP: 61692CBK3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  12393069 | PA      | $559466.51    | 0.04%             | 2054-06-15      | Variable      | 1.29%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                      | Freddie Mac REMICS                                                                                                                     | CUSIP: 3137H9AD1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   3035301 | PA      | $2978948.62   | 0.21%             | 2052-09-25      | Floating      | 5.17%                 | No            |                  2 | On Loan: No      |
| Morgan Stanley Capital I Trust                   | Morgan Stanley Capital I Trust 2021-L5                                                                                                 | CUSIP: 61691YAP6<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  10172391 | PA      | $521540.53    | 0.04%             | 2054-05-15      | Variable      | 1.40%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CHP9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  68921723 | PA      | $66782900.99  | 4.62%             | 2033-07-15      | Fixed         | 1.38%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                      | Freddie Mac REMICS                                                                                                                     | CUSIP: 3137HJBF3<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   3653809 | PA      | $3647557.32   | 0.25%             | 2054-10-25      | Floating      | 5.25%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FTG43<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   3519182 | PA      | $272237.94    | 0.02%             | 2030-04-25      | Variable      | 1.91%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 9128283R9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  57009364 | PA      | $56287170.12  | 3.89%             | 2028-01-15      | Fixed         | 0.50%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 9128285W6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 113450663 | PA      | $112105494.41 | 7.75%             | 2029-01-15      | Fixed         | 0.88%                 | No            |                  2 | On Loan: No      |
| TOLEDO HOSPITAL/THE                              | Toledo Hospital/The                                                                                                                    | CUSIP: 889184AF4<br>LEI: 5493009DCR7NWV6K4T34 | Long             | DBT              | CORP              | US        |   2421000 | PA      | $2468555.00   | 0.17%             | 2028-11-15      | Fixed         | 5.33%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810TY4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  17414640 | PA      | $16050615.16  | 1.11%             | 2054-02-15      | Fixed         | 2.13%                 | No            |                  2 | On Loan: No      |
| Santander Drive Auto Receivables Trust           | Santander Drive Auto Receivables Trust 2025-1                                                                                          | CUSIP: 80288DAC0<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1200000 | PA      | $1204595.40   | 0.08%             | 2029-01-16      | Fixed         | 4.74%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38380LBW2<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   5665374 | PA      | $5709010.47   | 0.39%             | 2068-04-20      | Floating      | 4.99%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H4SM3<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   8215224 | PA      | $255364.49    | 0.02%             | 2031-12-25      | Variable      | 0.66%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810SB5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  26713391 | PA      | $19783785.06  | 1.37%             | 2048-02-15      | Fixed         | 1.00%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F62R7<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   3529812 | PA      | $193537.47    | 0.01%             | 2030-09-25      | Variable      | 1.26%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FQ2W2<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   2230372 | PA      | $2228233.10   | 0.15%             | 2029-09-25      | Floating      | 5.01%                 | No            |                  2 | On Loan: No      |
| SBNA Auto Lease Trust                            | SBNA Auto Lease Trust 2024-A                                                                                                           | CUSIP: 78414SAC8<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |     62062 | PA      | $62087.43     | 0.00%             | 2026-01-20      | Fixed         | 5.45%                 | Yes           |                  2 | On Loan: No      |
| Chicago Board of Trade                           | US 5YR NOTE (CBT) JUN25                                                                                                                | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       809 | NC      | $753848.16    | 0.05%             |  |  |  | No            |                  1 | On Loan: No      |
| Palmer Square Loan Funding Ltd                   | Palmer Square Loan Funding 2025-1 Ltd                                                                                                  | CUSIP: 69704CAC1<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   4300000 | PA      | $4241021.20   | 0.29%             | 2033-02-15      | Floating      | 5.52%                 | Yes           |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H4CH1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  49721062 | PA      | $1015711.80   | 0.07%             | 2031-11-25      | Variable      | 0.44%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FV5Q1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   9735635 | PA      | $555262.23    | 0.04%             | 2030-06-25      | Variable      | 1.48%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FXYZ5<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  54980294 | PA      | $1505266.98   | 0.10%             | 2031-01-25      | Variable      | 0.63%                 | No            |                  2 | On Loan: No      |
| BSPDF 2021-FL1 Issuer Ltd                        | BSPDF 2021-FL1 Issuer Ltd                                                                                                              | CUSIP: 055731AC7<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   3056500 | PA      | $3031170.78   | 0.21%             | 2036-10-15      | Floating      | 5.92%                 | Yes           |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CDX6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  74799020 | PA      | $67525031.59  | 4.67%             | 2032-01-15      | Fixed         | 0.13%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HFP33<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  28847080 | PA      | $934703.09    | 0.06%             | 2029-07-25      | Variable      | 1.01%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                           | US 2YR NOTE (CBT) JUN25                                                                                                                | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       770 | NC      | $681346.98    | 0.05%             |  |  |  | No            |                  1 | On Loan: No      |
| Westlake Automobile Receivables Trust            | Westlake Automobile Receivables Trust 2024-1                                                                                           | CUSIP: 96043RAC1<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    898684 | PA      | $898853.40    | 0.06%             | 2027-03-15      | Floating      | 4.92%                 | Yes           |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H5DT1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  50485813 | PA      | $1418939.11   | 0.10%             | 2031-12-25      | Variable      | 0.60%                 | No            |                  2 | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 912828ZZ6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 178340772 | PA      | $167458828.30 | 11.58%            | 2030-07-15      | Fixed         | 0.13%                 | No            |                  2 | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HKSB1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   7359327 | PA      | $184711.01    | 0.01%             | 2030-01-25      | Variable      | 0.57%                 | No            |                  2 | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B27 Mortgage Trust                                                                                                      | CUSIP: 08163HAG3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  20419293 | PA      | $1109907.02   | 0.08%             | 2054-07-15      | Variable      | 1.35%                 | No            |                  2 | On Loan: No      |
| CONSERVATION FUND                                | Conservation Fund A Nonprofit Corp/The                                                                                                 | CUSIP: 20848FAA8<br>LEI: N/A                  | Long             | DBT              | CORP              | US        |   1438000 | PA      | $1365742.60   | 0.09%             | 2029-12-15      | Fixed         | 3.47%                 | No            |                  2 | On Loan: No      |

### Signature

**Date Signed:** 2025-05-15

**Name of Applicant:** MFS SERIES TRUST IX

**Signature:** James Byrne

**Name of Signer:** James Byrne

**Title:** Assistant Treasurer