# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-26-010498
**Filing Date:** 2026-2
**Character Count:** 13141
**Document Hash:** 83b3d6943cea1f70010b591c14ee48bb
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-26-010498.hdr.sgml**: 20260206

**ACCESSION NUMBER**: 0001410368-26-010498

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260131

**FILED AS OF DATE**: 20260206

**DATE AS OF CHANGE**: 20260206

**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:** 26607333

**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 Reserves Fund (Series ID: S000052306)

| Class ID   | Class Name              | Ticker Symbol   |
|:---|:---|:---|
| C000164452 | UBS Prime Reserves Fund | UPRXX           |

# 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):** 2026-01-31

**Registrant Full Name:** UBS Series Funds

**CIK Number of Registrant:** 0001060517

**LEI of Registrant:** 54930058UKPXVB81RJ71

**Name of Series:** UBS Prime Reserves Fund

**LEI of Series:** 549300SZFUYVRC9F4568

**EDGAR Series Identifier:** S000052306

**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:** $15304446529.22

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $50684036.88

- **Net Assets of Series:** $15253762492.34

- **Number of Shares Outstanding (Series):** 15252913693.8700

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2026-01-02 | $13314910137.69           | $13987757706.09            | 51.9500%                  | 54.5800%                   |
| 2026-01-05 | $12843826237.41           | $13741520170.91            | 49.6900%                  | 53.1700%                   |
| 2026-01-06 | $12674139690.78           | $13379914636.78            | 49.0000%                  | 51.7300%                   |
| 2026-01-07 | $12472353526.73           | $13323974618.43            | 48.2100%                  | 51.5000%                   |
| 2026-01-08 | $12237498592.54           | $13137197178.74            | 47.6500%                  | 51.1500%                   |
| 2026-01-09 | $12577891444.03           | $13152752329.53            | 48.9400%                  | 51.1800%                   |
| 2026-01-12 | $12338701314.99           | $13038656195.59            | 48.2300%                  | 50.9700%                   |
| 2026-01-13 | $12528612154.44           | $13143571028.84            | 49.1300%                  | 51.5400%                   |
| 2026-01-14 | $12329176617.38           | $12944145336.98            | 48.4900%                  | 50.9100%                   |
| 2026-01-15 | $12175242821.18           | $13193982850.48            | 47.9600%                  | 51.9700%                   |
| 2026-01-16 | $12262921909.09           | $13381460055.19            | 48.0700%                  | 52.4600%                   |
| 2026-01-20 | $12273516971.87           | $13206300613.17            | 48.2300%                  | 51.9000%                   |
| 2026-01-21 | $12340610552.29           | $13030458699.59            | 48.4800%                  | 51.1900%                   |
| 2026-01-22 | $12499901492.93           | $12903809407.93            | 49.3500%                  | 50.9500%                   |
| 2026-01-23 | $12677598057.04           | $12931598057.04            | 49.9900%                  | 50.9900%                   |
| 2026-01-26 | $12655647980.04           | $13214447802.04            | 49.9500%                  | 52.1500%                   |
| 2026-01-27 | $12583551835.70           | $13187348605.70            | 49.3700%                  | 51.7400%                   |
| 2026-01-28 | $12052782466.56           | $12928267666.67            | 47.7600%                  | 51.2300%                   |
| 2026-01-29 | $11660462905.71           | $12985634221.24            | 46.1500%                  | 51.3900%                   |
| 2026-01-30 | $11789645085.94           | $13336229795.66            | 46.4400%                  | 52.5300%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2026-01-02 | 3.9200%             |
| 2026-01-05 | 3.9200%             |
| 2026-01-06 | 3.9100%             |
| 2026-01-07 | 3.9000%             |
| 2026-01-08 | 3.8900%             |
| 2026-01-09 | 3.8700%             |
| 2026-01-12 | 3.8600%             |
| 2026-01-13 | 3.8600%             |
| 2026-01-14 | 3.8500%             |
| 2026-01-15 | 3.8500%             |
| 2026-01-16 | 3.8500%             |
| 2026-01-20 | 3.8500%             |
| 2026-01-21 | 3.8500%             |
| 2026-01-22 | 3.8500%             |
| 2026-01-23 | 3.8400%             |
| 2026-01-26 | 3.8400%             |
| 2026-01-27 | 3.8400%             |
| 2026-01-28 | 3.8500%             |
| 2026-01-29 | 3.8500%             |
| 2026-01-30 | 3.8500%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2026-01-02 | 1.0001                      |
|  |  |
| 2026-01-05 | 1.0001                      |
|  |  |
| 2026-01-06 | 1.0001                      |
|  |  |
| 2026-01-07 | 1.0001                      |
|  |  |
| 2026-01-08 | 1.0001                      |
|  |  |
| 2026-01-09 | 1.0001                      |
|  |  |
| 2026-01-12 | 1.0001                      |
|  |  |
| 2026-01-13 | 1.0001                      |
|  |  |
| 2026-01-14 | 1.0001                      |
|  |  |
| 2026-01-15 | 1.0001                      |
|  |  |
| 2026-01-16 | 1.0000                      |
|  |  |
| 2026-01-20 | 1.0001                      |
|  |  |
| 2026-01-21 | 1.0001                      |
|  |  |
| 2026-01-22 | 1.0001                      |
|  |  |
| 2026-01-23 | 1.0000                      |
|  |  |
| 2026-01-26 | 1.0001                      |
|  |  |
| 2026-01-27 | 1.0001                      |
|  |  |
| 2026-01-28 | 1.0001                      |
|  |  |
| 2026-01-29 | 1.0001                      |
|  |  |
| 2026-01-30 | 1.0000                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1000000.00

- **Net Assets of Class:** $15253762492.34

- **Number of Shares Outstanding:** 15252913693.8700

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2026-01-02 | 1.0001          |
|  |  |
| 2026-01-05 | 1.0001          |
|  |  |
| 2026-01-06 | 1.0001          |
|  |  |
| 2026-01-07 | 1.0001          |
|  |  |
| 2026-01-08 | 1.0001          |
|  |  |
| 2026-01-09 | 1.0001          |
|  |  |
| 2026-01-12 | 1.0001          |
|  |  |
| 2026-01-13 | 1.0001          |
|  |  |
| 2026-01-14 | 1.0001          |
|  |  |
| 2026-01-15 | 1.0001          |
|  |  |
| 2026-01-16 | 1.0000          |
|  |  |
| 2026-01-20 | 1.0001          |
|  |  |
| 2026-01-21 | 1.0001          |
|  |  |
| 2026-01-22 | 1.0001          |
|  |  |
| 2026-01-23 | 1.0000          |
|  |  |
| 2026-01-26 | 1.0001          |
|  |  |
| 2026-01-27 | 1.0001          |
|  |  |
| 2026-01-28 | 1.0001          |
|  |  |
| 2026-01-29 | 1.0001          |
|  |  |
| 2026-01-30 | 1.0000          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2026-01-02 | $160455111.69             | $70611468.14            |
| 2026-01-05 | $104864485.00             | $91114405.93            |
| 2026-01-06 | $128029101.03             | $87394112.35            |
| 2026-01-07 | $101067869.15             | $89783514.14            |
| 2026-01-08 | $88674556.71              | $119437828.07           |
| 2026-01-09 | $135636163.20             | $91498180.33            |
| 2026-01-12 | $86144526.13              | $137559999.33           |
| 2026-01-13 | $96309646.00              | $108800384.31           |
| 2026-01-14 | $74594159.14              | $122186441.59           |
| 2026-01-15 | $74094301.60              | $100827563.19           |
| 2026-01-16 | $120808060.36             | $82782188.87            |
| 2026-01-20 | $119674452.72             | $124663490.16           |
| 2026-01-21 | $96156266.36              | $180287782.65           |
| 2026-01-22 | $81870510.40              | $97662295.39            |
| 2026-01-23 | $93337666.90              | $92282399.34            |
| 2026-01-26 | $112378879.44             | $105268159.53           |
| 2026-01-27 | $79181216.36              | $102163534.42           |
| 2026-01-28 | $79345874.36              | $98428437.21            |
| 2026-01-29 | $78352338.54              | $102716254.94           |
| 2026-01-30 | $161064832.62             | $130550223.36           |

**Total Gross Subscriptions (Month):** $2072040017.71

**Total Gross Redemptions (Month):** $2136018663.25

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2026-01-02 | 3.7400%           |
| 2026-01-05 | 3.7400%           |
| 2026-01-06 | 3.7300%           |
| 2026-01-07 | 3.7200%           |
| 2026-01-08 | 3.7100%           |
| 2026-01-09 | 3.6900%           |
| 2026-01-12 | 3.6800%           |
| 2026-01-13 | 3.6700%           |
| 2026-01-14 | 3.6700%           |
| 2026-01-15 | 3.6700%           |
| 2026-01-16 | 3.6700%           |
| 2026-01-20 | 3.6700%           |
| 2026-01-21 | 3.6700%           |
| 2026-01-22 | 3.6700%           |
| 2026-01-23 | 3.6600%           |
| 2026-01-26 | 3.6600%           |
| 2026-01-27 | 3.6600%           |
| 2026-01-28 | 3.6700%           |
| 2026-01-29 | 3.6700%           |
| 2026-01-30 | 3.6700%           |

## 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):** $15304446529.22
- **C.18.a - Value (excl. sponsor support):** $15304446529.22
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2026-02-02
- **C.12 - Maturity Date (WAL):** 2026-02-02
- **C.13 - Final Legal Maturity Date:** 2026-02-02
- **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:** 2026-02-06

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

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

**Title of Signing Officer:** Vice President