# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001145549-25-050831
**Filing Date:** 2025-8
**Character Count:** 14415
**Document Hash:** fd124523221165aa3267126c2d45a64a
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-050831.hdr.sgml**: 20250807

**ACCESSION NUMBER**: 0001145549-25-050831

**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:** 251193132

**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 Treasury Preferred Fund (Series ID: S000018677)

| Class ID   | Class Name                         | Ticker Symbol   |
|:---|:---|:---|
| C000051800 | UBS Select Treasury Preferred Fund | STPXX           |

# 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:** UBS Select Treasury Preferred Fund

**LEI of Series:** 549300DXQ8KM8WHPPG39

**EDGAR Series Identifier:** S000018677

**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:** $23145898002.29

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $83700016.66

- **Net Assets of Series:** $23062197985.63

- **Number of Shares Outstanding (Series):** 23062068120.7200

- **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 | $44115383982.40           | $45115383982.40            | 97.5800%                  | 99.7900%                   |
| 2025-07-02 | $44405119863.46           | $45405119863.46            | 97.5900%                  | 99.7900%                   |
| 2025-07-03 | $44116639754.62           | $45116639754.62            | 97.5400%                  | 99.7500%                   |
| 2025-07-07 | $45116179808.08           | $46116179808.08            | 97.6100%                  | 99.7800%                   |
| 2025-07-08 | $45762435994.10           | $46762435994.10            | 97.6400%                  | 99.7800%                   |
| 2025-07-09 | $46287391774.36           | $47287391774.36            | 97.6700%                  | 99.7800%                   |
| 2025-07-10 | $45100181304.33           | $46100181304.33            | 97.6000%                  | 99.7700%                   |
| 2025-07-11 | $45910015325.37           | $46910015325.37            | 97.6200%                  | 99.7500%                   |
| 2025-07-14 | $47371677154.17           | $48371677154.17            | 97.7100%                  | 99.7700%                   |
| 2025-07-15 | $46167400164.72           | $47167400164.72            | 97.6500%                  | 99.7700%                   |
| 2025-07-16 | $46691626658.12           | $47691626658.12            | 97.6800%                  | 99.7700%                   |
| 2025-07-17 | $44806366501.05           | $45806366501.05            | 97.5800%                  | 99.7600%                   |
| 2025-07-18 | $44175246197.75           | $45175246197.75            | 97.5200%                  | 99.7300%                   |
| 2025-07-21 | $44438033666.86           | $45438033666.86            | 97.5500%                  | 99.7400%                   |
| 2025-07-22 | $43993932532.22           | $44993932532.22            | 97.5200%                  | 99.7400%                   |
| 2025-07-23 | $44089006146.70           | $45089006146.70            | 97.5200%                  | 99.7300%                   |
| 2025-07-24 | $42805508062.63           | $43805508062.63            | 97.4500%                  | 99.7200%                   |
| 2025-07-25 | $43736932395.15           | $44736932395.15            | 97.4800%                  | 99.7100%                   |
| 2025-07-28 | $44790970142.13           | $45790970142.13            | 97.5500%                  | 99.7200%                   |
| 2025-07-29 | $43882618462.32           | $44882618462.32            | 97.4900%                  | 99.7200%                   |
| 2025-07-30 | $46215333539.53           | $46215333539.53            | 99.7200%                  | 99.7200%                   |
| 2025-07-31 | $42731477074.53           | $43731477074.53            | 97.6500%                  | 99.9400%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-07-01 | 4.4000%             |
| 2025-07-02 | 4.4000%             |
| 2025-07-03 | 4.3800%             |
| 2025-07-07 | 4.3700%             |
| 2025-07-08 | 4.3700%             |
| 2025-07-09 | 4.3700%             |
| 2025-07-10 | 4.3700%             |
| 2025-07-11 | 4.3700%             |
| 2025-07-14 | 4.3700%             |
| 2025-07-15 | 4.3700%             |
| 2025-07-16 | 4.3700%             |
| 2025-07-17 | 4.3700%             |
| 2025-07-18 | 4.3700%             |
| 2025-07-21 | 4.3600%             |
| 2025-07-22 | 4.3600%             |
| 2025-07-23 | 4.3500%             |
| 2025-07-24 | 4.3500%             |
| 2025-07-25 | 4.3700%             |
| 2025-07-28 | 4.3700%             |
| 2025-07-29 | 4.3800%             |
| 2025-07-30 | 4.3800%             |
| 2025-07-31 | 4.3900%             |

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

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

### Class: Single Class

- **Minimum Initial Investment:** $50000000.00

- **Net Assets of Class:** $23062197985.63

- **Number of Shares Outstanding:** 23062068120.7200

- **Expense Reimbursement/Waiver:** 796732.00

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

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-07-01 | $438566212.51             | $395348852.93           |
| 2025-07-02 | $302654845.47             | $376951807.93           |
| 2025-07-03 | $214649216.47             | $254445529.17           |
| 2025-07-07 | $356970687.18             | $371741424.84           |
| 2025-07-08 | $762450645.57             | $124470601.02           |
| 2025-07-09 | $305700171.81             | $342271853.23           |
| 2025-07-10 | $345392802.96             | $124892059.40           |
| 2025-07-11 | $423698346.50             | $184574539.67           |
| 2025-07-14 | $500124224.89             | $197275755.07           |
| 2025-07-15 | $382788849.26             | $245122253.79           |
| 2025-07-16 | $150494058.03             | $671756635.64           |
| 2025-07-17 | $126383179.08             | $805462648.34           |
| 2025-07-18 | $255528880.93             | $751499567.22           |
| 2025-07-21 | $167052271.39             | $564223618.42           |
| 2025-07-22 | $714006002.38             | $188825432.04           |
| 2025-07-23 | $104791124.46             | $258364085.39           |
| 2025-07-24 | $186914655.33             | $653766757.01           |
| 2025-07-25 | $530140530.22             | $137987770.90           |
| 2025-07-28 | $543430812.35             | $255491939.36           |
| 2025-07-29 | $350242153.84             | $293237140.68           |
| 2025-07-30 | $383608272.57             | $404999434.94           |
| 2025-07-31 | $672600851.18             | $881816313.16           |

**Total Gross Subscriptions (Month):** $8218188794.38

**Total Gross Redemptions (Month):** $8484526020.15

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-07-01 | 4.2600%           |
| 2025-07-02 | 4.2600%           |
| 2025-07-03 | 4.2400%           |
| 2025-07-07 | 4.2300%           |
| 2025-07-08 | 4.2300%           |
| 2025-07-09 | 4.2300%           |
| 2025-07-10 | 4.2300%           |
| 2025-07-11 | 4.2300%           |
| 2025-07-14 | 4.2300%           |
| 2025-07-15 | 4.2300%           |
| 2025-07-16 | 4.2300%           |
| 2025-07-17 | 4.2300%           |
| 2025-07-18 | 4.2300%           |
| 2025-07-21 | 4.2300%           |
| 2025-07-22 | 4.2200%           |
| 2025-07-23 | 4.2200%           |
| 2025-07-24 | 4.2100%           |
| 2025-07-25 | 4.2300%           |
| 2025-07-28 | 4.2300%           |
| 2025-07-29 | 4.2400%           |
| 2025-07-30 | 4.2400%           |
| 2025-07-31 | 4.2500%           |

**Beneficial/Record Owner Categories**
| Category                                                                    | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| State or municipal government entity (excluding governmental pension plans) |  | 11.8700%         | 0.0000%              |
| Other                                                                       | IND FID AS EXEC  | 5.9100%          | 0.0000%              |

## Part C: Schedule of Portfolio Securities

### Security 1: Treasury Master Fund

- **C.1 - Title:** Treasury Master Fund
- **C.6 - Investment Category:** Investment Company
- **Identifiers:** C.3 - CUSIP: 81699K911, C.3 - LEI: 549300XQ6V293JKF0677, C.5 - Other ID: 81699K911
- **C.18 - Value (incl. sponsor support):** $23145898002.29
- **C.18.a - Value (excl. sponsor support):** $23145898002.29
- **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