# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-25-014059
**Filing Date:** 2025-10
**Character Count:** 13778
**Document Hash:** f25e6c13819558d3c2c8bde34d14b2a1
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-25-014059.hdr.sgml**: 20251007

**ACCESSION NUMBER**: 0001410368-25-014059

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250930

**FILED AS OF DATE**: 20251007

**DATE AS OF CHANGE**: 20251007

**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:** 251379614

**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):** 2025-09-30

**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:** $18926714550.30

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $68997702.81

- **Net Assets of Series:** $18857716847.49

- **Number of Shares Outstanding (Series):** 18857615381.9200

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2025-09-02 | $45991940872.62           | $46991940872.62            | 97.7200%                  | 99.8500%                   |
| 2025-09-03 | $48550966314.50           | $49550966314.50            | 97.8400%                  | 99.8500%                   |
| 2025-09-04 | $46278899031.28           | $47278899031.28            | 97.7300%                  | 99.8400%                   |
| 2025-09-05 | $46334208049.77           | $47334208049.77            | 97.7100%                  | 99.8200%                   |
| 2025-09-08 | $46790460902.14           | $47790460902.14            | 97.7400%                  | 99.8300%                   |
| 2025-09-09 | $46172740218.03           | $47172740218.03            | 97.7100%                  | 99.8300%                   |
| 2025-09-10 | $46534106264.57           | $47534106264.57            | 97.7300%                  | 99.8300%                   |
| 2025-09-11 | $45507617491.35           | $46507617491.35            | 97.6700%                  | 99.8200%                   |
| 2025-09-12 | $46175363570.79           | $47175363570.79            | 97.6900%                  | 99.8000%                   |
| 2025-09-15 | $46528659364.82           | $47528659364.82            | 97.7200%                  | 99.8200%                   |
| 2025-09-16 | $45866488504.09           | $46866488504.09            | 97.6900%                  | 99.8200%                   |
| 2025-09-17 | $46708969930.03           | $46708969930.03            | 99.8100%                  | 99.8100%                   |
| 2025-09-18 | $45802298609.34           | $46802298609.34            | 97.6900%                  | 99.8200%                   |
| 2025-09-19 | $45139365624.81           | $46139365624.81            | 97.6400%                  | 99.8100%                   |
| 2025-09-22 | $45135073298.53           | $46135073298.53            | 97.6500%                  | 99.8100%                   |
| 2025-09-23 | $45594234044.02           | $46594234044.02            | 97.6700%                  | 99.8100%                   |
| 2025-09-24 | $45357679684.80           | $46357679684.80            | 97.6500%                  | 99.8100%                   |
| 2025-09-25 | $45496645791.23           | $46496645791.23            | 97.6600%                  | 99.8000%                   |
| 2025-09-26 | $45434096059.04           | $46434096059.04            | 97.6400%                  | 99.7900%                   |
| 2025-09-29 | $45126564978.49           | $46126564978.49            | 97.6300%                  | 99.7900%                   |
| 2025-09-30 | $45173938282.21           | $46173938282.21            | 97.6500%                  | 99.8100%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-09-02 | 4.3400%             |
| 2025-09-03 | 4.3400%             |
| 2025-09-04 | 4.3400%             |
| 2025-09-05 | 4.3400%             |
| 2025-09-08 | 4.3400%             |
| 2025-09-09 | 4.3400%             |
| 2025-09-10 | 4.3300%             |
| 2025-09-11 | 4.3300%             |
| 2025-09-12 | 4.3200%             |
| 2025-09-15 | 4.3200%             |
| 2025-09-16 | 4.3200%             |
| 2025-09-17 | 4.3100%             |
| 2025-09-18 | 4.3000%             |
| 2025-09-19 | 4.2400%             |
| 2025-09-22 | 4.2200%             |
| 2025-09-23 | 4.2000%             |
| 2025-09-24 | 4.1800%             |
| 2025-09-25 | 4.1800%             |
| 2025-09-26 | 4.1800%             |
| 2025-09-29 | 4.1800%             |
| 2025-09-30 | 4.1800%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-09-02 | 1.0002                      |
|  |  |
| 2025-09-03 | 1.0002                      |
|  |  |
| 2025-09-04 | 1.0002                      |
|  |  |
| 2025-09-05 | 1.0002                      |
|  |  |
| 2025-09-08 | 1.0002                      |
|  |  |
| 2025-09-09 | 1.0002                      |
|  |  |
| 2025-09-10 | 1.0002                      |
|  |  |
| 2025-09-11 | 1.0002                      |
|  |  |
| 2025-09-12 | 1.0002                      |
|  |  |
| 2025-09-15 | 1.0002                      |
|  |  |
| 2025-09-16 | 1.0002                      |
|  |  |
| 2025-09-17 | 1.0002                      |
|  |  |
| 2025-09-18 | 1.0002                      |
|  |  |
| 2025-09-19 | 1.0002                      |
|  |  |
| 2025-09-22 | 1.0001                      |
|  |  |
| 2025-09-23 | 1.0002                      |
|  |  |
| 2025-09-24 | 1.0001                      |
|  |  |
| 2025-09-25 | 1.0001                      |
|  |  |
| 2025-09-26 | 1.0001                      |
|  |  |
| 2025-09-29 | 1.0001                      |
|  |  |
| 2025-09-30 | 1.0001                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1000000.00

- **Net Assets of Class:** $18857716847.49

- **Number of Shares Outstanding:** 18857615381.9200

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-09-02 | 1.0002          |
|  |  |
| 2025-09-03 | 1.0002          |
|  |  |
| 2025-09-04 | 1.0002          |
|  |  |
| 2025-09-05 | 1.0002          |
|  |  |
| 2025-09-08 | 1.0002          |
|  |  |
| 2025-09-09 | 1.0002          |
|  |  |
| 2025-09-10 | 1.0002          |
|  |  |
| 2025-09-11 | 1.0002          |
|  |  |
| 2025-09-12 | 1.0002          |
|  |  |
| 2025-09-15 | 1.0002          |
|  |  |
| 2025-09-16 | 1.0002          |
|  |  |
| 2025-09-17 | 1.0002          |
|  |  |
| 2025-09-18 | 1.0002          |
|  |  |
| 2025-09-19 | 1.0002          |
|  |  |
| 2025-09-22 | 1.0001          |
|  |  |
| 2025-09-23 | 1.0002          |
|  |  |
| 2025-09-24 | 1.0001          |
|  |  |
| 2025-09-25 | 1.0001          |
|  |  |
| 2025-09-26 | 1.0001          |
|  |  |
| 2025-09-29 | 1.0001          |
|  |  |
| 2025-09-30 | 1.0001          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-09-02 | $164237417.09             | $943503197.43           |
| 2025-09-03 | $621402657.93             | $104832499.88           |
| 2025-09-04 | $98909575.47              | $420043837.08           |
| 2025-09-05 | $106603881.33             | $192823613.35           |
| 2025-09-08 | $137374626.69             | $171144298.34           |
| 2025-09-09 | $89106497.39              | $299707645.10           |
| 2025-09-10 | $78264859.88              | $305397482.78           |
| 2025-09-11 | $128325442.51             | $115951688.62           |
| 2025-09-12 | $322088547.02             | $117535668.73           |
| 2025-09-15 | $193414437.65             | $141031254.70           |
| 2025-09-16 | $121989071.06             | $312915350.81           |
| 2025-09-17 | $95693447.49              | $357409974.47           |
| 2025-09-18 | $164382731.62             | $104241683.10           |
| 2025-09-19 | $155290152.60             | $205510827.72           |
| 2025-09-22 | $54710025.63              | $262652467.43           |
| 2025-09-23 | $74317959.78              | $128158501.99           |
| 2025-09-24 | $153022190.76             | $454386235.99           |
| 2025-09-25 | $79303066.02              | $126689479.98           |
| 2025-09-26 | $319852978.41             | $113466021.57           |
| 2025-09-29 | $74595392.19              | $572102657.33           |
| 2025-09-30 | $247848278.77             | $498963678.11           |

**Total Gross Subscriptions (Month):** $3480733237.29

**Total Gross Redemptions (Month):** $5948468064.51

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-09-02 | 4.1600%           |
| 2025-09-03 | 4.1600%           |
| 2025-09-04 | 4.1600%           |
| 2025-09-05 | 4.1600%           |
| 2025-09-08 | 4.1600%           |
| 2025-09-09 | 4.1600%           |
| 2025-09-10 | 4.1500%           |
| 2025-09-11 | 4.1500%           |
| 2025-09-12 | 4.1400%           |
| 2025-09-15 | 4.1400%           |
| 2025-09-16 | 4.1400%           |
| 2025-09-17 | 4.1300%           |
| 2025-09-18 | 4.1200%           |
| 2025-09-19 | 4.0600%           |
| 2025-09-22 | 4.0400%           |
| 2025-09-23 | 4.0200%           |
| 2025-09-24 | 4.0000%           |
| 2025-09-25 | 4.0000%           |
| 2025-09-26 | 4.0000%           |
| 2025-09-29 | 4.0000%           |
| 2025-09-30 | 4.0100%           |

**Beneficial/Record Owner Categories**
| Category                  | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| Non-financial corporation |  | 5.0600%          | 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):** $18926714550.30
- **C.18.a - Value (excl. sponsor support):** $18926714550.30
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-10-01
- **C.12 - Maturity Date (WAL):** 2025-10-01
- **C.13 - Final Legal Maturity Date:** 2025-10-01
- **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:** 2025-10-07

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

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

**Title of Signing Officer:** Vice President