# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-26-022303
**Filing Date:** 2026-3
**Character Count:** 12928
**Document Hash:** a0fd0ee6ecdc3753fd40114d575b525b
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-26-022303.hdr.sgml**: 20260306

**ACCESSION NUMBER**: 0001410368-26-022303

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260228

**FILED AS OF DATE**: 20260306

**DATE AS OF CHANGE**: 20260306

**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:** 26730223

**BUSINESS ADDRESS:**
- **STREET 1:** C/O UBS ASSET MANAGEMENT (AMERICAS) LLC
- **STREET 2:** 1285 AVENUE OF THE AMERICAS
- **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:** 1285 AVENUE OF THE AMERICAS
- **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):** 2026-02-28

**Registrant Full Name:** UBS Series Funds

**CIK Number of Registrant:** 0001060517

**LEI of Registrant:** 54930058UKPXVB81RJ71

**Name of Series:** UBS Select 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:** $7997558057.86

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

- **Cash:** $0.00

- **Total Other Assets:** $53865.18

- **Total Liabilities:** $23116247.55

- **Net Assets of Series:** $7974495675.49

- **Number of Shares Outstanding (Series):** 7974301277.7700

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2026-02-02 | $18313392902.83           | $18313392902.83            | 99.9700%                  | 99.9700%                   |
| 2026-02-03 | $17673964911.76           | $17673964911.76            | 99.9600%                  | 99.9600%                   |
| 2026-02-04 | $18069708270.84           | $18069708270.84            | 99.9600%                  | 99.9600%                   |
| 2026-02-05 | $17929831826.12           | $17929831826.12            | 99.9600%                  | 99.9600%                   |
| 2026-02-06 | $17950045995.61           | $17950045995.61            | 99.9600%                  | 99.9600%                   |
| 2026-02-09 | $18759771477.55           | $18759771477.55            | 99.9600%                  | 99.9600%                   |
| 2026-02-10 | $17927212929.00           | $17927212929.00            | 99.9600%                  | 99.9600%                   |
| 2026-02-11 | $18283021138.31           | $18283021138.31            | 99.9600%                  | 99.9600%                   |
| 2026-02-12 | $17713538887.49           | $17713538887.49            | 99.9500%                  | 99.9500%                   |
| 2026-02-13 | $17826338493.91           | $17826338493.91            | 99.9500%                  | 99.9500%                   |
| 2026-02-17 | $17856107569.60           | $17856107569.60            | 99.9500%                  | 99.9500%                   |
| 2026-02-18 | $18400459663.05           | $18400459663.05            | 99.9500%                  | 99.9500%                   |
| 2026-02-19 | $17883502047.11           | $17883502047.11            | 99.9500%                  | 99.9500%                   |
| 2026-02-20 | $17959670108.28           | $17959670108.28            | 99.9400%                  | 99.9400%                   |
| 2026-02-23 | $18304421778.66           | $18304421778.66            | 99.9400%                  | 99.9400%                   |
| 2026-02-24 | $17817296479.23           | $17817296479.23            | 99.9400%                  | 99.9400%                   |
| 2026-02-25 | $17927872539.23           | $17927872539.23            | 99.9400%                  | 99.9400%                   |
| 2026-02-26 | $17847545095.02           | $17847545095.02            | 99.9400%                  | 99.9400%                   |
| 2026-02-27 | $17769717132.14           | $17769717132.14            | 99.9300%                  | 99.9300%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2026-02-02 | 3.7100%             |
| 2026-02-03 | 3.7100%             |
| 2026-02-04 | 3.7000%             |
| 2026-02-05 | 3.7000%             |
| 2026-02-06 | 3.7000%             |
| 2026-02-09 | 3.7000%             |
| 2026-02-10 | 3.7000%             |
| 2026-02-11 | 3.7000%             |
| 2026-02-12 | 3.7000%             |
| 2026-02-13 | 3.7000%             |
| 2026-02-17 | 3.7000%             |
| 2026-02-18 | 3.7000%             |
| 2026-02-19 | 3.7000%             |
| 2026-02-20 | 3.7000%             |
| 2026-02-23 | 3.7000%             |
| 2026-02-24 | 3.7000%             |
| 2026-02-25 | 3.7000%             |
| 2026-02-26 | 3.7000%             |
| 2026-02-27 | 3.7000%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2026-02-02 | 1.0001                      |
|  |  |
| 2026-02-03 | 1.0001                      |
|  |  |
| 2026-02-04 | 1.0001                      |
|  |  |
| 2026-02-05 | 1.0001                      |
|  |  |
| 2026-02-06 | 1.0001                      |
|  |  |
| 2026-02-09 | 1.0001                      |
|  |  |
| 2026-02-10 | 1.0001                      |
|  |  |
| 2026-02-11 | 1.0001                      |
|  |  |
| 2026-02-12 | 1.0001                      |
|  |  |
| 2026-02-13 | 1.0001                      |
|  |  |
| 2026-02-17 | 1.0001                      |
|  |  |
| 2026-02-18 | 1.0001                      |
|  |  |
| 2026-02-19 | 1.0001                      |
|  |  |
| 2026-02-20 | 1.0001                      |
|  |  |
| 2026-02-23 | 1.0001                      |
|  |  |
| 2026-02-24 | 1.0001                      |
|  |  |
| 2026-02-25 | 1.0001                      |
|  |  |
| 2026-02-26 | 1.0001                      |
|  |  |
| 2026-02-27 | 1.0001                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1.00

- **Net Assets of Class:** $7974495675.49

- **Number of Shares Outstanding:** 7974301277.7700

- **Expense Reimbursement/Waiver:** 28391.00

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2026-02-02 | 1.0001          |
|  |  |
| 2026-02-03 | 1.0001          |
|  |  |
| 2026-02-04 | 1.0001          |
|  |  |
| 2026-02-05 | 1.0001          |
|  |  |
| 2026-02-06 | 1.0001          |
|  |  |
| 2026-02-09 | 1.0001          |
|  |  |
| 2026-02-10 | 1.0001          |
|  |  |
| 2026-02-11 | 1.0001          |
|  |  |
| 2026-02-12 | 1.0001          |
|  |  |
| 2026-02-13 | 1.0001          |
|  |  |
| 2026-02-17 | 1.0001          |
|  |  |
| 2026-02-18 | 1.0001          |
|  |  |
| 2026-02-19 | 1.0001          |
|  |  |
| 2026-02-20 | 1.0001          |
|  |  |
| 2026-02-23 | 1.0001          |
|  |  |
| 2026-02-24 | 1.0001          |
|  |  |
| 2026-02-25 | 1.0001          |
|  |  |
| 2026-02-26 | 1.0001          |
|  |  |
| 2026-02-27 | 1.0001          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2026-02-02 | $73115001.34              | $51076175.37            |
| 2026-02-03 | $98638842.18              | $23101547.57            |
| 2026-02-04 | $85618650.20              | $55937928.56            |
| 2026-02-05 | $51957535.26              | $46456478.73            |
| 2026-02-06 | $47354528.95              | $51192133.08            |
| 2026-02-09 | $78057948.59              | $49851939.57            |
| 2026-02-10 | $80217877.91              | $44905701.48            |
| 2026-02-11 | $83874883.12              | $53632615.94            |
| 2026-02-12 | $83299244.35              | $59783141.78            |
| 2026-02-13 | $53402281.17              | $62910647.51            |
| 2026-02-17 | $68725353.52              | $66070471.25            |
| 2026-02-18 | $110640847.12             | $35694569.91            |
| 2026-02-19 | $75793524.72              | $113532173.31           |
| 2026-02-20 | $95515648.16              | $46443118.46            |
| 2026-02-23 | $22527899.14              | $83141362.95            |
| 2026-02-24 | $28115000.12              | $73215826.76            |
| 2026-02-25 | $51215080.30              | $55889189.86            |
| 2026-02-26 | $64714185.88              | $53680745.43            |
| 2026-02-27 | $60076749.65              | $61090350.99            |

**Total Gross Subscriptions (Month):** $1312861081.68

**Total Gross Redemptions (Month):** $1087606118.51

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-02-02 | 3.5300%           |
| 2026-02-03 | 3.5300%           |
| 2026-02-04 | 3.5200%           |
| 2026-02-05 | 3.5200%           |
| 2026-02-06 | 3.5200%           |
| 2026-02-09 | 3.5200%           |
| 2026-02-10 | 3.5200%           |
| 2026-02-11 | 3.5200%           |
| 2026-02-12 | 3.5200%           |
| 2026-02-13 | 3.5200%           |
| 2026-02-17 | 3.5200%           |
| 2026-02-18 | 3.5200%           |
| 2026-02-19 | 3.5200%           |
| 2026-02-20 | 3.5200%           |
| 2026-02-23 | 3.5200%           |
| 2026-02-24 | 3.5200%           |
| 2026-02-25 | 3.5200%           |
| 2026-02-26 | 3.5200%           |
| 2026-02-27 | 3.5200%           |

## 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: 5299000M97HC3J8TJ387
- **C.18 - Value (incl. sponsor support):** $7997558057.86
- **C.18.a - Value (excl. sponsor support):** $7997558057.86
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2026-03-02
- **C.12 - Maturity Date (WAL):** 2026-03-02
- **C.13 - Final Legal Maturity Date:** 2026-03-02
- **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:** 2026-03-06

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

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

**Title of Signing Officer:** Vice President