# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001145549-25-046127
**Filing Date:** 2025-7
**Character Count:** 13263
**Document Hash:** 3969e2da8cbea9be008066d56794e251
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-046127.hdr.sgml**: 20250708

**ACCESSION NUMBER**: 0001145549-25-046127

**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:** 251110727

**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):** 2025-06-30

**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:** $6373093259.42

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

- **Cash:** $0.00

- **Total Other Assets:** $90108.18

- **Total Liabilities:** $23090042.17

- **Net Assets of Series:** $6350093325.43

- **Number of Shares Outstanding (Series):** 6350013025.0900

- **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 | $11582000510.80           | $11582000510.80            | 99.9100%                  | 99.9100%                   |
| 2025-06-03 | $11155845626.11           | $11155845626.11            | 99.9000%                  | 99.9000%                   |
| 2025-06-04 | $11638285341.77           | $11638285341.77            | 99.9000%                  | 99.9000%                   |
| 2025-06-05 | $11317436481.34           | $11317436481.34            | 99.8900%                  | 99.8900%                   |
| 2025-06-06 | $11291544731.08           | $11291544731.08            | 99.8800%                  | 99.8800%                   |
| 2025-06-09 | $11238030223.40           | $11238030223.40            | 99.8800%                  | 99.8800%                   |
| 2025-06-10 | $11232162748.78           | $11232162748.78            | 99.8800%                  | 99.8800%                   |
| 2025-06-11 | $11189452676.40           | $11189452676.40            | 99.8700%                  | 99.8700%                   |
| 2025-06-12 | $11422324937.68           | $11422324937.68            | 99.8700%                  | 99.8700%                   |
| 2025-06-13 | $11389599277.42           | $11389599277.42            | 99.8700%                  | 99.8700%                   |
| 2025-06-16 | $11652403878.32           | $11652403878.32            | 99.8700%                  | 99.8700%                   |
| 2025-06-17 | $11508414786.95           | $11508414786.95            | 99.8600%                  | 99.8600%                   |
| 2025-06-18 | $11960191631.89           | $11960191631.89            | 99.8600%                  | 99.8600%                   |
| 2025-06-20 | $11523617944.27           | $11523617944.27            | 99.8500%                  | 99.8500%                   |
| 2025-06-23 | $11634972398.19           | $11634972398.19            | 99.8500%                  | 99.8500%                   |
| 2025-06-24 | $11559722706.22           | $11559722706.22            | 99.8400%                  | 99.8400%                   |
| 2025-06-25 | $11909532409.54           | $11909532409.54            | 99.8400%                  | 99.8400%                   |
| 2025-06-26 | $11763553191.25           | $11763553191.25            | 99.8400%                  | 99.8400%                   |
| 2025-06-27 | $11707862211.32           | $11707862211.32            | 99.8300%                  | 99.8300%                   |
| 2025-06-30 | $11803550570.88           | $11803550570.88            | 99.8300%                  | 99.8300%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-06-02 | 4.3300%             |
| 2025-06-03 | 4.3300%             |
| 2025-06-04 | 4.3300%             |
| 2025-06-05 | 4.3200%             |
| 2025-06-06 | 4.3200%             |
| 2025-06-09 | 4.3200%             |
| 2025-06-10 | 4.3200%             |
| 2025-06-11 | 4.3200%             |
| 2025-06-12 | 4.3200%             |
| 2025-06-13 | 4.3200%             |
| 2025-06-16 | 4.3200%             |
| 2025-06-17 | 4.3100%             |
| 2025-06-18 | 4.3100%             |
| 2025-06-20 | 4.3100%             |
| 2025-06-23 | 4.3100%             |
| 2025-06-24 | 4.3100%             |
| 2025-06-25 | 4.3000%             |
| 2025-06-26 | 4.3000%             |
| 2025-06-27 | 4.2900%             |
| 2025-06-30 | 4.2900%             |

### 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 | 1.0002                      |
|  |  |
| 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:** $1.00

- **Net Assets of Class:** $6350093325.43

- **Number of Shares Outstanding:** 6350013025.0900

- **Expense Reimbursement/Waiver:** 44049.00

**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 | 1.0002          |
|  |  |
| 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 | $66081784.53              | $22516972.97            |
| 2025-06-03 | $61767760.47              | $583946131.42           |
| 2025-06-04 | $35767093.39              | $38243735.73            |
| 2025-06-05 | $73108630.04              | $39383270.34            |
| 2025-06-06 | $64420001.39              | $39585714.88            |
| 2025-06-09 | $45045094.13              | $34108269.86            |
| 2025-06-10 | $41250851.10              | $49736264.78            |
| 2025-06-11 | $37903997.82              | $47559379.30            |
| 2025-06-12 | $44221002.45              | $56818879.12            |
| 2025-06-13 | $53203221.19              | $33719124.62            |
| 2025-06-16 | $46727577.86              | $35016860.90            |
| 2025-06-17 | $61207837.18              | $35646435.27            |
| 2025-06-18 | $52797794.98              | $43730261.77            |
| 2025-06-20 | $43927874.74              | $41540495.13            |
| 2025-06-23 | $56701420.57              | $57638028.93            |
| 2025-06-24 | $36046159.56              | $60076355.81            |
| 2025-06-25 | $34497630.41              | $44364641.90            |
| 2025-06-26 | $59817848.92              | $32997093.66            |
| 2025-06-27 | $32356307.81              | $33385154.88            |
| 2025-06-30 | $29093184.61              | $37224082.15            |

**Total Gross Subscriptions (Month):** $975943073.15

**Total Gross Redemptions (Month):** $1367237153.42

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-06-02 | 4.1500%           |
| 2025-06-03 | 4.1500%           |
| 2025-06-04 | 4.1500%           |
| 2025-06-05 | 4.1400%           |
| 2025-06-06 | 4.1400%           |
| 2025-06-09 | 4.1400%           |
| 2025-06-10 | 4.1400%           |
| 2025-06-11 | 4.1400%           |
| 2025-06-12 | 4.1400%           |
| 2025-06-13 | 4.1400%           |
| 2025-06-16 | 4.1400%           |
| 2025-06-17 | 4.1300%           |
| 2025-06-18 | 4.1300%           |
| 2025-06-20 | 4.1300%           |
| 2025-06-23 | 4.1300%           |
| 2025-06-24 | 4.1300%           |
| 2025-06-25 | 4.1200%           |
| 2025-06-26 | 4.1200%           |
| 2025-06-27 | 4.1100%           |
| 2025-06-30 | 4.1100%           |

## 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):** $6373093259.42
- **C.18.a - Value (excl. sponsor support):** $6373093259.42
- **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