# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001145549-25-050829
**Filing Date:** 2025-8
**Character Count:** 13991
**Document Hash:** dfd3054de51211648df892c8fb50c0f5
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-050829.hdr.sgml**: 20250807

**ACCESSION NUMBER**: 0001145549-25-050829

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250731

**FILED AS OF DATE**: 20250807

**DATE AS OF CHANGE**: 20250807

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** UBS Series Funds
- **CENTRAL INDEX KEY:** 0001060517

**ORGANIZATION NAME:**
- **EIN:** 134010447
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0430

**FILING VALUES:**
- **FORM TYPE:** N-MFP3
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-08767
- **FILM NUMBER:** 251193130

**BUSINESS ADDRESS:**
- **STREET 1:** C/O UBS ASSET MANAGEMENT (AMERICAS) LLC
- **STREET 2:** 787 SEVENTH AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10019
- **BUSINESS PHONE:** 212-821-3000

**MAIL ADDRESS:**
- **STREET 1:** C/O UBS ASSET MANAGEMENT (AMERICAS) LLC
- **STREET 2:** 787 SEVENTH AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10019

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** UBS MONEY SERIES
- **DATE OF NAME CHANGE:** 20020716

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BRINSON MONEY SERIES
- **DATE OF NAME CHANGE:** 20010625

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MITCHELL HUTCHINS LIR MONEY SERIES
- **DATE OF NAME CHANGE:** 19990730

## Series and Classes Contracts Data

### UBS Select 100% US Treasury Institutional Fund (Series ID: S000084282)

| Class ID   | Class Name                                     | Ticker Symbol   |
|:---|:---|:---|
| C000248579 | UBS Select 100% US Treasury Institutional Fund | SIOXX           |

# Form N-MFP3: Monthly Schedule of Portfolio Holdings

## N-MFP: Filer Information
**Submission Type:** N-MFP3
**CIK:** 0001060517

### General Information

**Report for (YYYY-MM-DD):** 2025-07-31

**Registrant Full Name:** UBS Series Funds

**CIK Number of Registrant:** 0001060517

**LEI of Registrant:** 54930058UKPXVB81RJ71

**Name of Series:** 100% US Treasury Institutional Fund

**LEI of Series:** 529900KWG787B4G5P791

**EDGAR Series Identifier:** S000084282

**Total number of share classes in the series:** 1

**Is this the fund's final filing on Form N-MFP?:** No

**Has the fund acquired or merged with another fund?:** No

## Part A: Series-Level Information about the Fund

### Service Providers
| Role                          | Details                                                      | File/CIK Number   |
|:---|:---|:---|
| Investment Adviser            | UBS ASSET MANAGEMENT (AMERICAS) LLC                          | 801-34910         |
| Independent Public Accountant | Ernst & Young  LLP<br>City: New York<br>State: NY            |  |
| Administrator                 | UBS ASSET MANAGEMENT (AMERICAS) LLC                          |  |
| Transfer Agent                | BNY Mellon Investment Servicing (US) Inc.<br>CIK: 0000849542 | 084-01761         |

### Fund Characteristics & Assets

- **Securities Act File Number:** 333-52965

- **Is this a Feeder Fund?:** Yes

- **Is this a Master Fund?:** No

- **Is this series for insurance company separate accounts?:** No

- **Money Market Fund Category:** Government

- **Is this a Retail Money Market Fund?:** No

- **Is this a Government Money Market Fund?:** Yes

- **WAM:** 1 days

- **WAL:** 1 days

- **Total Value of Portfolio Securities:** $6486066323.88

- **Amortized Cost of Portfolio Securities:** $0.00

- **Cash:** $0.00

- **Total Other Assets:** $83164.05

- **Total Liabilities:** $23780802.35

- **Net Assets of Series:** $6462368685.58

- **Number of Shares Outstanding (Series):** 6462288103.6800

- **Does the fund seek to maintain a stable price per share?:** Yes

- **Stable Price Per Share:** $1.00

- **Is cash management vehicle an affiliated fund?:** No

- **Does the fund apply liquidity fees?:** No

### Daily & Weekly Liquid Assets
| Date       | Daily Liquid Assets ($)   | Weekly Liquid Assets ($)   | Daily Liquid Assets (%)   | Weekly Liquid Assets (%)   |
|:---|:---|:---|:---|:---|
| 2025-07-01 | $11518048290.58           | $11518048290.58            | 99.8200%                  | 99.8200%                   |
| 2025-07-02 | $12277557714.09           | $12277557714.09            | 99.8300%                  | 99.8300%                   |
| 2025-07-03 | $11639037464.50           | $11639037464.50            | 99.8100%                  | 99.8100%                   |
| 2025-07-07 | $12807372077.04           | $12807372077.04            | 99.8300%                  | 99.8300%                   |
| 2025-07-08 | $12040597575.94           | $12040597575.94            | 99.8200%                  | 99.8200%                   |
| 2025-07-09 | $12729379901.08           | $12729379901.08            | 99.8200%                  | 99.8200%                   |
| 2025-07-10 | $12507682738.30           | $12507682738.30            | 99.8200%                  | 99.8200%                   |
| 2025-07-11 | $12591985658.40           | $12591985658.40            | 99.8100%                  | 99.8100%                   |
| 2025-07-14 | $13284506619.95           | $13284506619.95            | 99.8200%                  | 99.8200%                   |
| 2025-07-15 | $12550349109.48           | $12550349109.48            | 99.8200%                  | 99.8200%                   |
| 2025-07-16 | $13225691083.80           | $13225691083.80            | 99.8200%                  | 99.8200%                   |
| 2025-07-17 | $12895449392.80           | $12895449392.80            | 99.8200%                  | 99.8200%                   |
| 2025-07-18 | $12906319611.97           | $12906319611.97            | 99.8100%                  | 99.8100%                   |
| 2025-07-21 | $13645059130.40           | $13645059130.40            | 99.8200%                  | 99.8200%                   |
| 2025-07-22 | $12798716661.10           | $12798716661.10            | 99.8000%                  | 99.8000%                   |
| 2025-07-23 | $13365838597.63           | $13365838597.63            | 99.8100%                  | 99.8100%                   |
| 2025-07-24 | $12751876245.32           | $12751876245.32            | 99.8000%                  | 99.8000%                   |
| 2025-07-25 | $12731115661.84           | $12731115661.84            | 99.7900%                  | 99.7900%                   |
| 2025-07-28 | $13918005094.18           | $13918005094.18            | 99.8100%                  | 99.8100%                   |
| 2025-07-29 | $12604453629.78           | $12604453629.78            | 99.7800%                  | 99.7800%                   |
| 2025-07-30 | $13589096686.89           | $13589096686.89            | 99.8000%                  | 99.8000%                   |
| 2025-07-31 | $12481870276.54           | $12481870276.54            | 99.9500%                  | 99.9500%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-07-01 | 4.2900%             |
| 2025-07-02 | 4.2800%             |
| 2025-07-03 | 4.2700%             |
| 2025-07-07 | 4.2700%             |
| 2025-07-08 | 4.2700%             |
| 2025-07-09 | 4.2800%             |
| 2025-07-10 | 4.2800%             |
| 2025-07-11 | 4.2900%             |
| 2025-07-14 | 4.2900%             |
| 2025-07-15 | 4.2900%             |
| 2025-07-16 | 4.2900%             |
| 2025-07-17 | 4.3000%             |
| 2025-07-18 | 4.3000%             |
| 2025-07-21 | 4.3100%             |
| 2025-07-22 | 4.3100%             |
| 2025-07-23 | 4.3100%             |
| 2025-07-24 | 4.3100%             |
| 2025-07-25 | 4.3200%             |
| 2025-07-28 | 4.3200%             |
| 2025-07-29 | 4.3200%             |
| 2025-07-30 | 4.3200%             |
| 2025-07-31 | 4.3300%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-07-01 | 1.0000                      |
|  |  |
| 2025-07-02 | 1.0001                      |
|  |  |
| 2025-07-03 | 1.0000                      |
|  |  |
| 2025-07-07 | 1.0000                      |
|  |  |
| 2025-07-08 | 1.0000                      |
|  |  |
| 2025-07-09 | 1.0001                      |
|  |  |
| 2025-07-10 | 1.0000                      |
|  |  |
| 2025-07-11 | 1.0001                      |
|  |  |
| 2025-07-14 | 1.0000                      |
|  |  |
| 2025-07-15 | 1.0000                      |
|  |  |
| 2025-07-16 | 1.0001                      |
|  |  |
| 2025-07-17 | 1.0000                      |
|  |  |
| 2025-07-18 | 1.0001                      |
|  |  |
| 2025-07-21 | 1.0001                      |
|  |  |
| 2025-07-22 | 1.0001                      |
|  |  |
| 2025-07-23 | 1.0000                      |
|  |  |
| 2025-07-24 | 1.0000                      |
|  |  |
| 2025-07-25 | 1.0001                      |
|  |  |
| 2025-07-28 | 1.0000                      |
|  |  |
| 2025-07-29 | 1.0001                      |
|  |  |
| 2025-07-30 | 1.0000                      |
|  |  |
| 2025-07-31 | 1.0000                      |
|  |  |

## Part B: Class-Level Information about the Fund

### Class: Single Class

- **Minimum Initial Investment:** $1.00

- **Net Assets of Class:** $6462368685.58

- **Number of Shares Outstanding:** 6462288103.6800

- **Expense Reimbursement/Waiver:** 44889.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-07-01 | 1.0000          |
|  |  |
| 2025-07-02 | 1.0001          |
|  |  |
| 2025-07-03 | 1.0000          |
|  |  |
| 2025-07-07 | 1.0000          |
|  |  |
| 2025-07-08 | 1.0000          |
|  |  |
| 2025-07-09 | 1.0001          |
|  |  |
| 2025-07-10 | 1.0000          |
|  |  |
| 2025-07-11 | 1.0001          |
|  |  |
| 2025-07-14 | 1.0000          |
|  |  |
| 2025-07-15 | 1.0000          |
|  |  |
| 2025-07-16 | 1.0001          |
|  |  |
| 2025-07-17 | 1.0000          |
|  |  |
| 2025-07-18 | 1.0001          |
|  |  |
| 2025-07-21 | 1.0001          |
|  |  |
| 2025-07-22 | 1.0001          |
|  |  |
| 2025-07-23 | 1.0000          |
|  |  |
| 2025-07-24 | 1.0000          |
|  |  |
| 2025-07-25 | 1.0001          |
|  |  |
| 2025-07-28 | 1.0000          |
|  |  |
| 2025-07-29 | 1.0001          |
|  |  |
| 2025-07-30 | 1.0000          |
|  |  |
| 2025-07-31 | 1.0000          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-07-01 | $77130043.56              | $35205720.30            |
| 2025-07-02 | $78029470.85              | $43072885.51            |
| 2025-07-03 | $47521923.76              | $18018227.86            |
| 2025-07-07 | $42276073.56              | $35761457.89            |
| 2025-07-08 | $29754999.71              | $62903770.42            |
| 2025-07-09 | $29291798.69              | $55566540.25            |
| 2025-07-10 | $55182370.39              | $32214753.64            |
| 2025-07-11 | $57065011.61              | $25035816.47            |
| 2025-07-14 | $34359896.10              | $29756322.73            |
| 2025-07-15 | $44646893.66              | $31018634.45            |
| 2025-07-16 | $30097053.39              | $37772678.94            |
| 2025-07-17 | $46895423.86              | $33517465.27            |
| 2025-07-18 | $45516428.20              | $35124270.49            |
| 2025-07-21 | $54703621.36              | $41260241.20            |
| 2025-07-22 | $66067135.74              | $34765892.01            |
| 2025-07-23 | $21366971.27              | $40832924.09            |
| 2025-07-24 | $54022513.01              | $52180660.78            |
| 2025-07-25 | $46164985.74              | $51397408.60            |
| 2025-07-28 | $46409553.50              | $70988627.24            |
| 2025-07-29 | $29393149.31              | $29441162.97            |
| 2025-07-30 | $57829457.50              | $34710299.67            |
| 2025-07-31 | $28733125.70              | $79637061.10            |

**Total Gross Subscriptions (Month):** $1022457900.47

**Total Gross Redemptions (Month):** $910182821.88

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-07-01 | 4.1100%           |
| 2025-07-02 | 4.1000%           |
| 2025-07-03 | 4.0900%           |
| 2025-07-07 | 4.0900%           |
| 2025-07-08 | 4.0900%           |
| 2025-07-09 | 4.1000%           |
| 2025-07-10 | 4.1000%           |
| 2025-07-11 | 4.1100%           |
| 2025-07-14 | 4.1100%           |
| 2025-07-15 | 4.1100%           |
| 2025-07-16 | 4.1100%           |
| 2025-07-17 | 4.1200%           |
| 2025-07-18 | 4.1200%           |
| 2025-07-21 | 4.1300%           |
| 2025-07-22 | 4.1300%           |
| 2025-07-23 | 4.1300%           |
| 2025-07-24 | 4.1300%           |
| 2025-07-25 | 4.1400%           |
| 2025-07-28 | 4.1400%           |
| 2025-07-29 | 4.1400%           |
| 2025-07-30 | 4.1400%           |
| 2025-07-31 | 4.1500%           |

## Part C: Schedule of Portfolio Securities

### Security 1: 100 [percent symbol] US Treasury Master Fund

- **C.1 - Title:** 100 [percent symbol] US Treasury Master Fund
- **C.6 - Investment Category:** Investment Company
- **Identifiers:** C.3 - CUSIP: 902656883, C.3 - LEI: 549300EBIIAXTNCMYQ69
- **C.18 - Value (incl. sponsor support):** $6486066323.88
- **C.18.a - Value (excl. sponsor support):** $6486066323.88
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-08-01
- **C.12 - Maturity Date (WAL):** 2025-08-01
- **C.13 - Final Legal Maturity Date:** 2025-08-01
- **Characteristics:** C.9 Eligible Security? Yes, C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

## N-MFP: Signatures

**Registrant:** UBS Series Funds

**Date:** 2025-08-07

**By:** /s/Rose Ann Bubloski

**Name of Signing Officer:** Rose Ann Bubloski

**Title of Signing Officer:** Vice President