# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001145549-25-046118
**Filing Date:** 2025-7
**Character Count:** 13546
**Document Hash:** 46d683458026bc100aa0020710637c1d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-046118.hdr.sgml**: 20250708

**ACCESSION NUMBER**: 0001145549-25-046118

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250630

**FILED AS OF DATE**: 20250708

**DATE AS OF CHANGE**: 20250708

**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:** 251110718

**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):** 2025-06-30

**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:** $23409693929.84

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $81158718.44

- **Net Assets of Series:** $23328535211.40

- **Number of Shares Outstanding (Series):** 23328405346.4900

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2025-06-02 | $44277021600.01           | $45277021600.01            | 97.6700%                  | 99.8800%                   |
| 2025-06-03 | $43838139039.24           | $44838139039.24            | 97.6500%                  | 99.8800%                   |
| 2025-06-04 | $43728586929.14           | $44728586929.14            | 97.6400%                  | 99.8700%                   |
| 2025-06-05 | $44027539093.24           | $45027539093.24            | 97.6500%                  | 99.8600%                   |
| 2025-06-06 | $43550162165.56           | $44550162165.56            | 97.6000%                  | 99.8400%                   |
| 2025-06-09 | $43117217873.32           | $44117217873.32            | 97.5800%                  | 99.8500%                   |
| 2025-06-10 | $43594876404.37           | $44594876404.37            | 97.6100%                  | 99.8500%                   |
| 2025-06-11 | $43556589437.46           | $44556589437.46            | 97.6000%                  | 99.8400%                   |
| 2025-06-12 | $43362005263.51           | $44362005263.51            | 97.5900%                  | 99.8400%                   |
| 2025-06-13 | $43693285316.93           | $44693285316.93            | 97.5800%                  | 99.8200%                   |
| 2025-06-16 | $43745500399.62           | $44745500399.62            | 97.6000%                  | 99.8300%                   |
| 2025-06-17 | $43807269303.51           | $44807269303.51            | 97.6000%                  | 99.8300%                   |
| 2025-06-18 | $44306818528.98           | $44306818528.98            | 99.8100%                  | 99.8100%                   |
| 2025-06-20 | $43448251734.09           | $43448251734.09            | 97.5600%                  | 97.5600%                   |
| 2025-06-23 | $43414318083.02           | $44414318083.02            | 97.5700%                  | 99.8200%                   |
| 2025-06-24 | $43383212964.32           | $44383212964.32            | 97.5600%                  | 99.8100%                   |
| 2025-06-25 | $42777233307.49           | $43777233307.49            | 97.5300%                  | 99.8100%                   |
| 2025-06-26 | $43608242330.73           | $44608242330.73            | 97.5700%                  | 99.8000%                   |
| 2025-06-27 | $45902932157.55           | $46902932157.55            | 97.6600%                  | 99.7900%                   |
| 2025-06-30 | $45678671375.21           | $46678671375.21            | 97.6600%                  | 99.8000%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-06-02 | 4.3900%             |
| 2025-06-03 | 4.3900%             |
| 2025-06-04 | 4.3800%             |
| 2025-06-05 | 4.3700%             |
| 2025-06-06 | 4.3500%             |
| 2025-06-09 | 4.3500%             |
| 2025-06-10 | 4.3500%             |
| 2025-06-11 | 4.3500%             |
| 2025-06-12 | 4.3500%             |
| 2025-06-13 | 4.3500%             |
| 2025-06-16 | 4.3500%             |
| 2025-06-17 | 4.3500%             |
| 2025-06-18 | 4.3500%             |
| 2025-06-20 | 4.3500%             |
| 2025-06-23 | 4.3500%             |
| 2025-06-24 | 4.3500%             |
| 2025-06-25 | 4.3500%             |
| 2025-06-26 | 4.3600%             |
| 2025-06-27 | 4.3900%             |
| 2025-06-30 | 4.3900%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-06-02 | 1.0001                      |
|  |  |
| 2025-06-03 | 1.0001                      |
|  |  |
| 2025-06-04 | 1.0001                      |
|  |  |
| 2025-06-05 | 1.0001                      |
|  |  |
| 2025-06-06 | 1.0001                      |
|  |  |
| 2025-06-09 | 1.0001                      |
|  |  |
| 2025-06-10 | 1.0001                      |
|  |  |
| 2025-06-11 | 1.0001                      |
|  |  |
| 2025-06-12 | 1.0001                      |
|  |  |
| 2025-06-13 | 1.0001                      |
|  |  |
| 2025-06-16 | 1.0001                      |
|  |  |
| 2025-06-17 | 1.0001                      |
|  |  |
| 2025-06-18 | 1.0001                      |
|  |  |
| 2025-06-20 | 1.0001                      |
|  |  |
| 2025-06-23 | 1.0001                      |
|  |  |
| 2025-06-24 | 1.0001                      |
|  |  |
| 2025-06-25 | 1.0001                      |
|  |  |
| 2025-06-26 | 1.0001                      |
|  |  |
| 2025-06-27 | 1.0001                      |
|  |  |
| 2025-06-30 | 1.0001                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $50000000.00

- **Net Assets of Class:** $23328535211.40

- **Number of Shares Outstanding:** 23328405346.4900

- **Expense Reimbursement/Waiver:** 750690.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-06-02 | 1.0001          |
|  |  |
| 2025-06-03 | 1.0001          |
|  |  |
| 2025-06-04 | 1.0001          |
|  |  |
| 2025-06-05 | 1.0001          |
|  |  |
| 2025-06-06 | 1.0001          |
|  |  |
| 2025-06-09 | 1.0001          |
|  |  |
| 2025-06-10 | 1.0001          |
|  |  |
| 2025-06-11 | 1.0001          |
|  |  |
| 2025-06-12 | 1.0001          |
|  |  |
| 2025-06-13 | 1.0001          |
|  |  |
| 2025-06-16 | 1.0001          |
|  |  |
| 2025-06-17 | 1.0001          |
|  |  |
| 2025-06-18 | 1.0001          |
|  |  |
| 2025-06-20 | 1.0001          |
|  |  |
| 2025-06-23 | 1.0001          |
|  |  |
| 2025-06-24 | 1.0001          |
|  |  |
| 2025-06-25 | 1.0001          |
|  |  |
| 2025-06-26 | 1.0001          |
|  |  |
| 2025-06-27 | 1.0001          |
|  |  |
| 2025-06-30 | 1.0001          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-06-02 | $367697888.89             | $297749312.38           |
| 2025-06-03 | $533745963.99             | $236482685.95           |
| 2025-06-04 | $521655176.94             | $584703332.61           |
| 2025-06-05 | $144090723.77             | $267493734.66           |
| 2025-06-06 | $391710284.24             | $552808586.47           |
| 2025-06-09 | $90506957.63              | $231410205.62           |
| 2025-06-10 | $602331374.47             | $136540626.26           |
| 2025-06-11 | $313232827.90             | $296812248.67           |
| 2025-06-12 | $751137946.38             | $238372262.72           |
| 2025-06-13 | $301466446.31             | $281046943.27           |
| 2025-06-16 | $444513861.35             | $589649400.53           |
| 2025-06-17 | $354437840.99             | $289215469.63           |
| 2025-06-18 | $516295624.10             | $1031508508.68          |
| 2025-06-20 | $641694946.87             | $442697858.04           |
| 2025-06-23 | $277093982.20             | $279763155.64           |
| 2025-06-24 | $242595048.98             | $519004165.68           |
| 2025-06-25 | $650833157.61             | $613835102.39           |
| 2025-06-26 | $413440135.80             | $166201962.72           |
| 2025-06-27 | $590347477.47             | $261068126.14           |
| 2025-06-30 | $733469188.68             | $1430966418.23          |

**Total Gross Subscriptions (Month):** $8882296854.57

**Total Gross Redemptions (Month):** $8747330106.29

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-06-02 | 4.2500%           |
| 2025-06-03 | 4.2500%           |
| 2025-06-04 | 4.2400%           |
| 2025-06-05 | 4.2400%           |
| 2025-06-06 | 4.2200%           |
| 2025-06-09 | 4.2100%           |
| 2025-06-10 | 4.2100%           |
| 2025-06-11 | 4.2100%           |
| 2025-06-12 | 4.2100%           |
| 2025-06-13 | 4.2100%           |
| 2025-06-16 | 4.2100%           |
| 2025-06-17 | 4.2100%           |
| 2025-06-18 | 4.2100%           |
| 2025-06-20 | 4.2100%           |
| 2025-06-23 | 4.2100%           |
| 2025-06-24 | 4.2100%           |
| 2025-06-25 | 4.2100%           |
| 2025-06-26 | 4.2200%           |
| 2025-06-27 | 4.2500%           |
| 2025-06-30 | 4.2500%           |

**Beneficial/Record Owner Categories**
| Category                                                                    | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| State or municipal government entity (excluding governmental pension plans) |  | 15.6000%         | 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):** $23409693929.84
- **C.18.a - Value (excl. sponsor support):** $23409693929.84
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-07-01
- **C.12 - Maturity Date (WAL):** 2025-07-01
- **C.13 - Final Legal Maturity Date:** 2025-07-01
- **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:** 2025-07-08

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

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

**Title of Signing Officer:** Vice President