# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-26-022298
**Filing Date:** 2026-3
**Character Count:** 12822
**Document Hash:** 1afdf7826529a112e3eca50e01fb02da
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-26-022298.hdr.sgml**: 20260306

**ACCESSION NUMBER**: 0001410368-26-022298

**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:** 26730216

**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 Prime Preferred Fund (Series ID: S000052307)

| Class ID   | Class Name               | Ticker Symbol   |
|:---|:---|:---|
| C000164453 | UBS Prime Preferred Fund | UPPXX           |

# 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 Prime Preferred Fund

**LEI of Series:** 5493001YQBD9A4ZH6D79

**EDGAR Series Identifier:** S000052307

**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:** Prime

- **Is this a Retail Money Market Fund?:** Yes

- **Is this a Government Money Market Fund?:** No

- **WAM:** 1 days

- **WAL:** 1 days

- **Total Value of Portfolio Securities:** $9877667239.75

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $29310076.26

- **Net Assets of Series:** $9848357163.49

- **Number of Shares Outstanding (Series):** 9847689443.6810

- **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 | $11762069009.21           | $13613950839.68            | 46.0700%                  | 53.3200%                   |
| 2026-02-03 | $11667479819.89           | $13557517271.99            | 45.9600%                  | 53.4000%                   |
| 2026-02-04 | $11974609245.60           | $13454748045.60            | 46.8200%                  | 52.6100%                   |
| 2026-02-05 | $11820852612.78           | $13171894699.62            | 46.5100%                  | 51.8300%                   |
| 2026-02-06 | $11639228466.03           | $12930278186.56            | 45.8500%                  | 50.9300%                   |
| 2026-02-09 | $11976239574.22           | $13057505124.78            | 47.1700%                  | 51.4300%                   |
| 2026-02-10 | $12139964635.80           | $13356117370.51            | 47.5400%                  | 52.3000%                   |
| 2026-02-11 | $12318026531.56           | $13261651398.06            | 48.4700%                  | 52.1800%                   |
| 2026-02-12 | $12506428246.28           | $13608852593.78            | 49.0100%                  | 53.3400%                   |
| 2026-02-13 | $12020208780.02           | $13510477651.42            | 47.0700%                  | 52.9000%                   |
| 2026-02-17 | $11775066071.03           | $13245639308.13            | 46.2500%                  | 52.0200%                   |
| 2026-02-18 | $11799280577.07           | $13144974827.77            | 46.3000%                  | 51.5800%                   |
| 2026-02-19 | $12520299128.04           | $12997154564.74            | 49.4100%                  | 51.3000%                   |
| 2026-02-20 | $12116261316.17           | $12878740605.16            | 47.8000%                  | 50.8100%                   |
| 2026-02-23 | $12123513453.71           | $12948965353.64            | 48.2500%                  | 51.5400%                   |
| 2026-02-24 | $12045904565.81           | $13261136308.07            | 48.0900%                  | 52.9400%                   |
| 2026-02-25 | $11968739140.51           | $13259015074.14            | 47.9300%                  | 53.1000%                   |
| 2026-02-26 | $12301525954.41           | $13238162849.11            | 49.3000%                  | 53.0500%                   |
| 2026-02-27 | $12102791837.89           | $13296311126.89            | 48.5300%                  | 53.3100%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2026-02-02 | 3.8500%             |
| 2026-02-03 | 3.8500%             |
| 2026-02-04 | 3.8500%             |
| 2026-02-05 | 3.8500%             |
| 2026-02-06 | 3.8300%             |
| 2026-02-09 | 3.8300%             |
| 2026-02-10 | 3.8200%             |
| 2026-02-11 | 3.8200%             |
| 2026-02-12 | 3.8200%             |
| 2026-02-13 | 3.8200%             |
| 2026-02-17 | 3.8200%             |
| 2026-02-18 | 3.8300%             |
| 2026-02-19 | 3.8300%             |
| 2026-02-20 | 3.8300%             |
| 2026-02-23 | 3.8300%             |
| 2026-02-24 | 3.8300%             |
| 2026-02-25 | 3.8200%             |
| 2026-02-26 | 3.8200%             |
| 2026-02-27 | 3.8200%             |

### 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 | 1.0000                      |
|  |  |
| 2026-02-17 | 1.0000                      |
|  |  |
| 2026-02-18 | 1.0001                      |
|  |  |
| 2026-02-19 | 1.0001                      |
|  |  |
| 2026-02-20 | 1.0000                      |
|  |  |
| 2026-02-23 | 1.0001                      |
|  |  |
| 2026-02-24 | 1.0001                      |
|  |  |
| 2026-02-25 | 1.0001                      |
|  |  |
| 2026-02-26 | 1.0001                      |
|  |  |
| 2026-02-27 | 1.0000                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $50000000.00

- **Net Assets of Class:** $9848357163.49

- **Number of Shares Outstanding:** 9847689443.6810

- **Expense Reimbursement/Waiver:** 307026.00

**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 | 1.0000          |
|  |  |
| 2026-02-17 | 1.0000          |
|  |  |
| 2026-02-18 | 1.0001          |
|  |  |
| 2026-02-19 | 1.0001          |
|  |  |
| 2026-02-20 | 1.0000          |
|  |  |
| 2026-02-23 | 1.0001          |
|  |  |
| 2026-02-24 | 1.0001          |
|  |  |
| 2026-02-25 | 1.0001          |
|  |  |
| 2026-02-26 | 1.0001          |
|  |  |
| 2026-02-27 | 1.0000          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2026-02-02 | $118824724.80             | $56732717.03            |
| 2026-02-03 | $69080152.57              | $86385505.72            |
| 2026-02-04 | $55494602.04              | $65092892.27            |
| 2026-02-05 | $104715348.07             | $76927278.40            |
| 2026-02-06 | $37029798.11              | $55978466.78            |
| 2026-02-09 | $51987412.05              | $55542908.05            |
| 2026-02-10 | $37329665.82              | $46496718.00            |
| 2026-02-11 | $36580982.09              | $55900987.41            |
| 2026-02-12 | $40276866.35              | $57718000.80            |
| 2026-02-13 | $67627052.79              | $83459956.31            |
| 2026-02-17 | $35131418.99              | $61394800.07            |
| 2026-02-18 | $69146282.41              | $51029775.53            |
| 2026-02-19 | $87516624.71              | $49438753.89            |
| 2026-02-20 | $32366486.43              | $92034939.37            |
| 2026-02-23 | $40495716.02              | $104604408.67           |
| 2026-02-24 | $69727274.30              | $79024824.42            |
| 2026-02-25 | $31378910.80              | $79540683.40            |
| 2026-02-26 | $40942207.09              | $43778220.07            |
| 2026-02-27 | $55956764.19              | $75951409.23            |

**Total Gross Subscriptions (Month):** $1081608289.63

**Total Gross Redemptions (Month):** $1277033245.42

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-02-02 | 3.7100%           |
| 2026-02-03 | 3.7100%           |
| 2026-02-04 | 3.7100%           |
| 2026-02-05 | 3.7100%           |
| 2026-02-06 | 3.6900%           |
| 2026-02-09 | 3.6900%           |
| 2026-02-10 | 3.6800%           |
| 2026-02-11 | 3.6800%           |
| 2026-02-12 | 3.6800%           |
| 2026-02-13 | 3.6800%           |
| 2026-02-17 | 3.6800%           |
| 2026-02-18 | 3.6900%           |
| 2026-02-19 | 3.6900%           |
| 2026-02-20 | 3.6900%           |
| 2026-02-23 | 3.6900%           |
| 2026-02-24 | 3.6900%           |
| 2026-02-25 | 3.6800%           |
| 2026-02-26 | 3.6800%           |
| 2026-02-27 | 3.6800%           |

## Part C: Schedule of Portfolio Securities

### Security 1: Prime CNAV Master Fund

- **C.1 - Title:** Prime CNAV Master Fund
- **C.6 - Investment Category:** Investment Company
- **Identifiers:** C.3 - CUSIP: 927XQC905, C.3 - LEI: 549300K8VKMIOPMVLW91, C.5 - Other ID: 927XQC905
- **C.18 - Value (incl. sponsor support):** $9877667239.75
- **C.18.a - Value (excl. sponsor support):** $9877667239.75
- **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