# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-26-022304
**Filing Date:** 2026-3
**Character Count:** 16455
**Document Hash:** 93aa2e71c183c4a801b7ad1d03e05dff
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-26-022304.hdr.sgml**: 20260306

**ACCESSION NUMBER**: 0001410368-26-022304

**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:** 26730224

**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 Preferred Fund (Series ID: S000084283)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000248580 | Class P      | STAXX           |
| C000250059 | Class T      | SOPXX           |

# 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 Preferred Fund

**LEI of Series:** 529900FTKZBAKZ4ON106

**EDGAR Series Identifier:** S000084283

**Total number of share classes in the series:** 2

**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:** $9261069843.28

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

- **Cash:** $0.00

- **Total Other Assets:** $45280.67

- **Total Liabilities:** $26987392.44

- **Net Assets of Series:** $9234127731.51

- **Number of Shares Outstanding (Series):** 9233931628.6500

- **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: Class P

- **Minimum Initial Investment:** $1.00

- **Net Assets of Class:** $528765443.47

- **Number of Shares Outstanding:** 528752687.5800

- **Expense Reimbursement/Waiver:** 18695.00

**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 | $4045171.46               | $2858060.72             |
| 2026-02-03 | $9050775.38               | $6570176.55             |
| 2026-02-04 | $4331475.60               | $3354623.02             |
| 2026-02-05 | $18808510.10              | $4901317.97             |
| 2026-02-06 | $6432945.10               | $6664236.52             |
| 2026-02-09 | $14188597.86              | $2976318.71             |
| 2026-02-10 | $4125544.82               | $9496366.79             |
| 2026-02-11 | $1923797.53               | $5536635.97             |
| 2026-02-12 | $5060778.90               | $3989828.96             |
| 2026-02-13 | $3847161.66               | $1620953.53             |
| 2026-02-17 | $934399.61                | $4133969.91             |
| 2026-02-18 | $2455608.92               | $4637374.66             |
| 2026-02-19 | $12013019.93              | $3175112.92             |
| 2026-02-20 | $12293593.10              | $2074140.12             |
| 2026-02-23 | $5533190.12               | $4405503.22             |
| 2026-02-24 | $6526903.07               | $10857486.25            |
| 2026-02-25 | $5884000.65               | $3450837.04             |
| 2026-02-26 | $4566053.91               | $6148205.11             |
| 2026-02-27 | $2338842.40               | $3611146.95             |

**Total Gross Subscriptions (Month):** $124360370.12

**Total Gross Redemptions (Month):** $90462294.92

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-02-02 | 3.5700%           |
| 2026-02-03 | 3.5700%           |
| 2026-02-04 | 3.5600%           |
| 2026-02-05 | 3.5600%           |
| 2026-02-06 | 3.5600%           |
| 2026-02-09 | 3.5600%           |
| 2026-02-10 | 3.5600%           |
| 2026-02-11 | 3.5600%           |
| 2026-02-12 | 3.5600%           |
| 2026-02-13 | 3.5600%           |
| 2026-02-17 | 3.5600%           |
| 2026-02-18 | 3.5600%           |
| 2026-02-19 | 3.5600%           |
| 2026-02-20 | 3.5600%           |
| 2026-02-23 | 3.5600%           |
| 2026-02-24 | 3.5600%           |
| 2026-02-25 | 3.5600%           |
| 2026-02-26 | 3.5600%           |
| 2026-02-27 | 3.5600%           |

**Beneficial/Record Owner Categories**
| Category        | Other Category   | Record Owner %   | Beneficial Owner %   |
|:---|:---|:---|:---|
| Retail investor |  | 7.7000%          | 0.0000%              |

### Class: Class T

- **Minimum Initial Investment:** $5000000.00

- **Net Assets of Class:** $8705362288.04

- **Number of Shares Outstanding:** 8705178941.0700

- **Expense Reimbursement/Waiver:** 310384.00

**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 | $53786003.37              | $37583599.72            |
| 2026-02-03 | $14521683.32              | $5115977.02             |
| 2026-02-04 | $25033452.17              | $2819359.54             |
| 2026-02-05 | $26730430.00              | $20949415.65            |
| 2026-02-06 | $28995952.65              | $9045631.32             |
| 2026-02-09 | $31416697.74              | $5782139.71             |
| 2026-02-10 | $29099671.77              | $149173099.20           |
| 2026-02-11 | $11748664.78              | $104765526.82           |
| 2026-02-12 | $25902691.24              | $28593046.30            |
| 2026-02-13 | $1334360.21               | $61511834.78            |
| 2026-02-17 | $41351994.59              | $8605493.49             |
| 2026-02-18 | $85024861.98              | $84533895.68            |
| 2026-02-19 | $11112452.95              | $33857850.02            |
| 2026-02-20 | $36243738.26              | $23893001.59            |
| 2026-02-23 | $26309730.75              | $38775856.77            |
| 2026-02-24 | $920381.25                | $24188271.45            |
| 2026-02-25 | $11470037.22              | $71810506.18            |
| 2026-02-26 | $25549104.11              | $32878398.09            |
| 2026-02-27 | $14555936.73              | $5250435.30             |

**Total Gross Subscriptions (Month):** $501107845.09

**Total Gross Redemptions (Month):** $749133338.63

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-02-02 | 3.5700%           |
| 2026-02-03 | 3.5700%           |
| 2026-02-04 | 3.5600%           |
| 2026-02-05 | 3.5600%           |
| 2026-02-06 | 3.5600%           |
| 2026-02-09 | 3.5600%           |
| 2026-02-10 | 3.5600%           |
| 2026-02-11 | 3.5600%           |
| 2026-02-12 | 3.5600%           |
| 2026-02-13 | 3.5600%           |
| 2026-02-17 | 3.5600%           |
| 2026-02-18 | 3.5600%           |
| 2026-02-19 | 3.5600%           |
| 2026-02-20 | 3.5600%           |
| 2026-02-23 | 3.5600%           |
| 2026-02-24 | 3.5600%           |
| 2026-02-25 | 3.5600%           |
| 2026-02-26 | 3.5600%           |
| 2026-02-27 | 3.5600%           |

## 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):** $9261069843.28
- **C.18.a - Value (excl. sponsor support):** $9261069843.28
- **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