# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-25-021487
**Filing Date:** 2025-11
**Character Count:** 14356
**Document Hash:** fd1c6a12bb5f02731cc1138085765a3d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-25-021487.hdr.sgml**: 20251107

**ACCESSION NUMBER**: 0001410368-25-021487

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251031

**FILED AS OF DATE**: 20251107

**DATE AS OF CHANGE**: 20251107

**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:** 251461894

**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):** 2025-10-31

**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:** $7437989726.41

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

- **Cash:** $0.00

- **Total Other Assets:** $26924.80

- **Total Liabilities:** $26992988.51

- **Net Assets of Series:** $7411023662.70

- **Number of Shares Outstanding (Series):** 7410919619.4800

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2025-10-01 | $13511201591.67           | $13511201591.67            | 99.8600%                  | 99.8600%                   |
| 2025-10-02 | $13632321872.42           | $13632321872.42            | 99.8500%                  | 99.8500%                   |
| 2025-10-03 | $13809759146.48           | $13809759146.48            | 99.8500%                  | 99.8500%                   |
| 2025-10-06 | $14256924424.97           | $14256924424.97            | 99.8500%                  | 99.8500%                   |
| 2025-10-07 | $13742953082.16           | $13742953082.16            | 99.8500%                  | 99.8500%                   |
| 2025-10-08 | $14734062738.51           | $14734062738.51            | 99.8500%                  | 99.8500%                   |
| 2025-10-09 | $14153451169.69           | $14153451169.69            | 99.8500%                  | 99.8500%                   |
| 2025-10-10 | $14145513295.99           | $14145513295.99            | 99.8400%                  | 99.8400%                   |
| 2025-10-13 | $0.00                     | $0.00                      | 0.0000%                   | 0.0000%                    |
| 2025-10-14 | $13886845846.69           | $13886845846.69            | 99.8300%                  | 99.8300%                   |
| 2025-10-15 | $14034680469.34           | $14034680469.34            | 99.8400%                  | 99.8400%                   |
| 2025-10-16 | $14201537280.93           | $14201537280.93            | 99.8400%                  | 99.8400%                   |
| 2025-10-17 | $14145896870.14           | $14145896870.14            | 99.8400%                  | 99.8400%                   |
| 2025-10-20 | $14299114210.17           | $14299114210.17            | 99.8400%                  | 99.8400%                   |
| 2025-10-21 | $14035679106.49           | $14035679106.49            | 99.8300%                  | 99.8300%                   |
| 2025-10-22 | $14474130375.05           | $14474130375.05            | 99.8300%                  | 99.8300%                   |
| 2025-10-23 | $14190069292.69           | $14190069292.69            | 99.8300%                  | 99.8300%                   |
| 2025-10-24 | $14224104332.77           | $14224104332.77            | 99.8200%                  | 99.8200%                   |
| 2025-10-27 | $14392773230.79           | $14392773230.79            | 99.8200%                  | 99.8200%                   |
| 2025-10-28 | $14295971799.39           | $14295971799.39            | 99.8200%                  | 99.8200%                   |
| 2025-10-29 | $14622223321.32           | $14622223321.32            | 99.8200%                  | 99.8200%                   |
| 2025-10-30 | $14479977427.96           | $14479977427.96            | 99.8200%                  | 99.8200%                   |
| 2025-10-31 | $14487202041.56           | $14487202041.56            | 99.9700%                  | 99.9700%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-10-01 | 4.1700%             |
| 2025-10-02 | 4.1700%             |
| 2025-10-03 | 4.1500%             |
| 2025-10-06 | 4.1500%             |
| 2025-10-07 | 4.1400%             |
| 2025-10-08 | 4.1400%             |
| 2025-10-09 | 4.1400%             |
| 2025-10-10 | 4.1200%             |
| 2025-10-13 | 0.0000%             |
| 2025-10-14 | 4.1200%             |
| 2025-10-15 | 4.1100%             |
| 2025-10-16 | 4.1100%             |
| 2025-10-17 | 4.1000%             |
| 2025-10-20 | 4.1000%             |
| 2025-10-21 | 4.1000%             |
| 2025-10-22 | 4.0900%             |
| 2025-10-23 | 4.0900%             |
| 2025-10-24 | 4.0800%             |
| 2025-10-27 | 4.0800%             |
| 2025-10-28 | 4.0700%             |
| 2025-10-29 | 4.0700%             |
| 2025-10-30 | 4.0600%             |
| 2025-10-31 | 4.0500%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-10-01 | 1.0002                      |
|  |  |
| 2025-10-02 | 1.0002                      |
|  |  |
| 2025-10-03 | 1.0001                      |
|  |  |
| 2025-10-06 | 1.0001                      |
|  |  |
| 2025-10-07 | 1.0001                      |
|  |  |
| 2025-10-08 | 1.0001                      |
|  |  |
| 2025-10-09 | 1.0001                      |
|  |  |
| 2025-10-10 | 1.0001                      |
|  |  |
| 2025-10-13 | 0.0000                      |
|  |  |
| 2025-10-14 | 1.0001                      |
|  |  |
| 2025-10-15 | 1.0001                      |
|  |  |
| 2025-10-16 | 1.0001                      |
|  |  |
| 2025-10-17 | 1.0001                      |
|  |  |
| 2025-10-20 | 1.0001                      |
|  |  |
| 2025-10-21 | 1.0001                      |
|  |  |
| 2025-10-22 | 1.0001                      |
|  |  |
| 2025-10-23 | 1.0001                      |
|  |  |
| 2025-10-24 | 1.0001                      |
|  |  |
| 2025-10-27 | 1.0002                      |
|  |  |
| 2025-10-28 | 1.0002                      |
|  |  |
| 2025-10-29 | 1.0001                      |
|  |  |
| 2025-10-30 | 1.0001                      |
|  |  |
| 2025-10-31 | 1.0001                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1.00

- **Net Assets of Class:** $7411023662.70

- **Number of Shares Outstanding:** 7410919619.4800

- **Expense Reimbursement/Waiver:** 52380.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-10-01 | 1.0002          |
|  |  |
| 2025-10-02 | 1.0002          |
|  |  |
| 2025-10-03 | 1.0001          |
|  |  |
| 2025-10-06 | 1.0001          |
|  |  |
| 2025-10-07 | 1.0001          |
|  |  |
| 2025-10-08 | 1.0001          |
|  |  |
| 2025-10-09 | 1.0001          |
|  |  |
| 2025-10-10 | 1.0001          |
|  |  |
| 2025-10-13 | 0.0000          |
|  |  |
| 2025-10-14 | 1.0001          |
|  |  |
| 2025-10-15 | 1.0001          |
|  |  |
| 2025-10-16 | 1.0001          |
|  |  |
| 2025-10-17 | 1.0001          |
|  |  |
| 2025-10-20 | 1.0001          |
|  |  |
| 2025-10-21 | 1.0001          |
|  |  |
| 2025-10-22 | 1.0001          |
|  |  |
| 2025-10-23 | 1.0001          |
|  |  |
| 2025-10-24 | 1.0001          |
|  |  |
| 2025-10-27 | 1.0002          |
|  |  |
| 2025-10-28 | 1.0002          |
|  |  |
| 2025-10-29 | 1.0001          |
|  |  |
| 2025-10-30 | 1.0001          |
|  |  |
| 2025-10-31 | 1.0001          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-10-01 | $116538427.49             | $67899898.37            |
| 2025-10-02 | $86013828.57              | $59540867.45            |
| 2025-10-03 | $203925332.62             | $51112663.87            |
| 2025-10-06 | $48814189.56              | $46195770.88            |
| 2025-10-07 | $76747296.66              | $57409592.99            |
| 2025-10-08 | $90761504.05              | $62405290.32            |
| 2025-10-09 | $38863459.25              | $74498491.67            |
| 2025-10-10 | $93007070.14              | $58287210.10            |
| 2025-10-13 | $0.00                     | $0.00                   |
| 2025-10-14 | $71495708.43              | $129809136.51           |
| 2025-10-15 | $69706539.22              | $116505993.06           |
| 2025-10-16 | $66390640.97              | $43465145.44            |
| 2025-10-17 | $49677813.31              | $64416219.35            |
| 2025-10-20 | $54021284.53              | $34115785.96            |
| 2025-10-21 | $76193529.75              | $60831478.73            |
| 2025-10-22 | $72653580.15              | $30567662.00            |
| 2025-10-23 | $46778940.15              | $37557959.99            |
| 2025-10-24 | $41020252.78              | $33977416.41            |
| 2025-10-27 | $80378427.26              | $41093323.25            |
| 2025-10-28 | $105011538.68             | $74657238.06            |
| 2025-10-29 | $248860438.41             | $80779594.66            |
| 2025-10-30 | $39681764.17              | $117610772.65           |
| 2025-10-31 | $63056468.25              | $82947702.39            |

**Total Gross Subscriptions (Month):** $1839598034.40

**Total Gross Redemptions (Month):** $1425685214.11

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-10-01 | 3.9900%           |
| 2025-10-02 | 3.9900%           |
| 2025-10-03 | 3.9700%           |
| 2025-10-06 | 3.9700%           |
| 2025-10-07 | 3.9600%           |
| 2025-10-08 | 3.9600%           |
| 2025-10-09 | 3.9600%           |
| 2025-10-10 | 3.9400%           |
| 2025-10-13 | 0.0000%           |
| 2025-10-14 | 3.9400%           |
| 2025-10-15 | 3.9300%           |
| 2025-10-16 | 3.9300%           |
| 2025-10-17 | 3.9200%           |
| 2025-10-20 | 3.9200%           |
| 2025-10-21 | 3.9200%           |
| 2025-10-22 | 3.9100%           |
| 2025-10-23 | 3.9100%           |
| 2025-10-24 | 3.9000%           |
| 2025-10-27 | 3.9000%           |
| 2025-10-28 | 3.8900%           |
| 2025-10-29 | 3.8900%           |
| 2025-10-30 | 3.8800%           |
| 2025-10-31 | 3.8700%           |

## 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):** $7437989726.41
- **C.18.a - Value (excl. sponsor support):** $7437989726.41
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-11-03
- **C.12 - Maturity Date (WAL):** 2025-11-03
- **C.13 - Final Legal Maturity Date:** 2025-11-03
- **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:** 2025-11-07

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

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

**Title of Signing Officer:** Vice President