# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001145549-25-038877
**Filing Date:** 2025-6
**Character Count:** 13778
**Document Hash:** 8bb00b4f16079cfb1ea2c827ba0bdf92
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-038877.hdr.sgml**: 20250606

**ACCESSION NUMBER**: 0001145549-25-038877

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250531

**FILED AS OF DATE**: 20250606

**DATE AS OF CHANGE**: 20250606

**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:** 251029846

**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 Institutional Fund (Series ID: S000002682)

| Class ID   | Class Name                             | Ticker Symbol   |
|:---|:---|:---|
| C000007334 | UBS Select Treasury Institutional Fund | SETXX           |

# 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):** 2025-05-31

**Registrant Full Name:** UBS Series Funds

**CIK Number of Registrant:** 0001060517

**LEI of Registrant:** 54930058UKPXVB81RJ71

**Name of Series:** UBS Select Treasury Institutional Fund

**LEI of Series:** 549300OA0OSRYE6ZYO90

**EDGAR Series Identifier:** S000002682

**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:** $19328384274.97

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $69198777.39

- **Net Assets of Series:** $19259185497.58

- **Number of Shares Outstanding (Series):** 19259084032.0100

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2025-05-01 | $41546483228.14           | $42546483228.14            | 97.6100%                  | 99.9600%                   |
| 2025-05-02 | $41882913353.96           | $42882913353.96            | 97.6100%                  | 99.9400%                   |
| 2025-05-05 | $41542793890.51           | $42542793890.51            | 97.6000%                  | 99.9500%                   |
| 2025-05-06 | $41983189311.18           | $42983189311.18            | 97.6200%                  | 99.9500%                   |
| 2025-05-07 | $42753519784.82           | $42753519784.82            | 99.9400%                  | 99.9400%                   |
| 2025-05-08 | $41602840331.60           | $42602840331.60            | 97.6100%                  | 99.9500%                   |
| 2025-05-09 | $41581700142.94           | $42581700142.94            | 97.5900%                  | 99.9300%                   |
| 2025-05-12 | $42220795613.29           | $43220795613.29            | 97.6200%                  | 99.9400%                   |
| 2025-05-13 | $42640974122.46           | $43640974122.46            | 97.6400%                  | 99.9300%                   |
| 2025-05-14 | $42666046294.32           | $43666046294.32            | 97.6400%                  | 99.9300%                   |
| 2025-05-15 | $43639088387.15           | $44639088387.15            | 97.6900%                  | 99.9300%                   |
| 2025-05-16 | $43402077953.90           | $44402077953.90            | 97.6600%                  | 99.9100%                   |
| 2025-05-19 | $43698010049.85           | $44698010049.85            | 97.6800%                  | 99.9200%                   |
| 2025-05-20 | $43067375182.98           | $44067375182.98            | 97.6500%                  | 99.9100%                   |
| 2025-05-21 | $43161374345.64           | $44161374345.64            | 97.6500%                  | 99.9100%                   |
| 2025-05-22 | $44533071525.56           | $45533071525.56            | 97.7200%                  | 99.9100%                   |
| 2025-05-23 | $43892283395.21           | $44892283395.21            | 97.6500%                  | 99.8800%                   |
| 2025-05-27 | $43105476187.28           | $44105476187.28            | 97.6300%                  | 99.8900%                   |
| 2025-05-28 | $42120279185.66           | $43120279185.66            | 97.5700%                  | 99.8900%                   |
| 2025-05-29 | $43674115102.32           | $44674115102.32            | 97.6500%                  | 99.8900%                   |
| 2025-05-30 | $44324313890.45           | $45324313890.45            | 97.6700%                  | 99.8700%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-05-01 | 4.3800%             |
| 2025-05-02 | 4.3800%             |
| 2025-05-05 | 4.3800%             |
| 2025-05-06 | 4.3700%             |
| 2025-05-07 | 4.3700%             |
| 2025-05-08 | 4.3600%             |
| 2025-05-09 | 4.3600%             |
| 2025-05-12 | 4.3500%             |
| 2025-05-13 | 4.3600%             |
| 2025-05-14 | 4.3600%             |
| 2025-05-15 | 4.3600%             |
| 2025-05-16 | 4.3700%             |
| 2025-05-19 | 4.3700%             |
| 2025-05-20 | 4.3700%             |
| 2025-05-21 | 4.3700%             |
| 2025-05-22 | 4.3700%             |
| 2025-05-23 | 4.3600%             |
| 2025-05-27 | 4.3600%             |
| 2025-05-28 | 4.3700%             |
| 2025-05-29 | 4.3700%             |
| 2025-05-30 | 4.3900%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-05-01 | 1.0001                      |
|  |  |
| 2025-05-02 | 1.0001                      |
|  |  |
| 2025-05-05 | 1.0001                      |
|  |  |
| 2025-05-06 | 1.0001                      |
|  |  |
| 2025-05-07 | 1.0001                      |
|  |  |
| 2025-05-08 | 1.0001                      |
|  |  |
| 2025-05-09 | 1.0001                      |
|  |  |
| 2025-05-12 | 1.0001                      |
|  |  |
| 2025-05-13 | 1.0001                      |
|  |  |
| 2025-05-14 | 1.0001                      |
|  |  |
| 2025-05-15 | 1.0001                      |
|  |  |
| 2025-05-16 | 1.0001                      |
|  |  |
| 2025-05-19 | 1.0001                      |
|  |  |
| 2025-05-20 | 1.0001                      |
|  |  |
| 2025-05-21 | 1.0001                      |
|  |  |
| 2025-05-22 | 1.0001                      |
|  |  |
| 2025-05-23 | 1.0001                      |
|  |  |
| 2025-05-27 | 1.0001                      |
|  |  |
| 2025-05-28 | 1.0001                      |
|  |  |
| 2025-05-29 | 1.0001                      |
|  |  |
| 2025-05-30 | 1.0001                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1000000.00

- **Net Assets of Class:** $19259185497.58

- **Number of Shares Outstanding:** 19259084032.0100

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-05-01 | 1.0001          |
|  |  |
| 2025-05-02 | 1.0001          |
|  |  |
| 2025-05-05 | 1.0001          |
|  |  |
| 2025-05-06 | 1.0001          |
|  |  |
| 2025-05-07 | 1.0001          |
|  |  |
| 2025-05-08 | 1.0001          |
|  |  |
| 2025-05-09 | 1.0001          |
|  |  |
| 2025-05-12 | 1.0001          |
|  |  |
| 2025-05-13 | 1.0001          |
|  |  |
| 2025-05-14 | 1.0001          |
|  |  |
| 2025-05-15 | 1.0001          |
|  |  |
| 2025-05-16 | 1.0001          |
|  |  |
| 2025-05-19 | 1.0001          |
|  |  |
| 2025-05-20 | 1.0001          |
|  |  |
| 2025-05-21 | 1.0001          |
|  |  |
| 2025-05-22 | 1.0001          |
|  |  |
| 2025-05-23 | 1.0001          |
|  |  |
| 2025-05-27 | 1.0001          |
|  |  |
| 2025-05-28 | 1.0001          |
|  |  |
| 2025-05-29 | 1.0001          |
|  |  |
| 2025-05-30 | 1.0001          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-05-01 | $636890838.17             | $78453417.51            |
| 2025-05-02 | $140406180.38             | $97636143.96            |
| 2025-05-05 | $106120980.01             | $260830734.02           |
| 2025-05-06 | $144469479.65             | $115010744.46           |
| 2025-05-07 | $74501006.74              | $125589754.45           |
| 2025-05-08 | $183791140.80             | $141862220.63           |
| 2025-05-09 | $149346438.84             | $105793650.47           |
| 2025-05-12 | $137143091.56             | $91477755.28            |
| 2025-05-13 | $268568343.66             | $85537095.02            |
| 2025-05-14 | $134004562.06             | $78006267.69            |
| 2025-05-15 | $383073938.23             | $100319334.44           |
| 2025-05-16 | $133048327.57             | $181619911.17           |
| 2025-05-19 | $89540468.37              | $67948461.21            |
| 2025-05-20 | $164189099.09             | $92337471.14            |
| 2025-05-21 | $126246324.59             | $115179560.18           |
| 2025-05-22 | $279283230.55             | $105292831.62           |
| 2025-05-23 | $90919926.62              | $135275085.11           |
| 2025-05-27 | $89154625.75              | $154339861.69           |
| 2025-05-28 | $95648401.33              | $489826455.35           |
| 2025-05-29 | $138826940.98             | $180610094.00           |
| 2025-05-30 | $1038802603.09            | $75460162.99            |

**Total Gross Subscriptions (Month):** $4603975948.04

**Total Gross Redemptions (Month):** $2878407012.39

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-05-01 | 4.2000%           |
| 2025-05-02 | 4.2000%           |
| 2025-05-05 | 4.2000%           |
| 2025-05-06 | 4.1900%           |
| 2025-05-07 | 4.1900%           |
| 2025-05-08 | 4.1800%           |
| 2025-05-09 | 4.1800%           |
| 2025-05-12 | 4.1800%           |
| 2025-05-13 | 4.1800%           |
| 2025-05-14 | 4.1800%           |
| 2025-05-15 | 4.1800%           |
| 2025-05-16 | 4.1900%           |
| 2025-05-19 | 4.1900%           |
| 2025-05-20 | 4.1900%           |
| 2025-05-21 | 4.1900%           |
| 2025-05-22 | 4.1900%           |
| 2025-05-23 | 4.1800%           |
| 2025-05-27 | 4.1900%           |
| 2025-05-28 | 4.1900%           |
| 2025-05-29 | 4.1900%           |
| 2025-05-30 | 4.2100%           |

**Beneficial/Record Owner Categories**
| Category                  | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| Non-financial corporation |  | 8.1500%          | 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):** $19328384274.97
- **C.18.a - Value (excl. sponsor support):** $19328384274.97
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-06-02
- **C.12 - Maturity Date (WAL):** 2025-06-02
- **C.13 - Final Legal Maturity Date:** 2025-06-02
- **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:** 2025-06-06

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

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

**Title of Signing Officer:** Vice President