# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001145549-25-058048
**Filing Date:** 2025-9
**Character Count:** 13488
**Document Hash:** bd7fd1438ad1c5c22a156a1cb4e2b1bc
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-25-058048.hdr.sgml**: 20250908

**ACCESSION NUMBER**: 0001145549-25-058048

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250831

**FILED AS OF DATE**: 20250908

**DATE AS OF CHANGE**: 20250908

**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:** 251299401

**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 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):** 2025-08-31

**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:** $15059613800.38

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $57367124.52

- **Net Assets of Series:** $15002246675.86

- **Number of Shares Outstanding (Series):** 15001397876.9100

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2025-08-01 | $10574662992.08           | $13417434698.08            | 42.5100%                  | 53.9400%                   |
| 2025-08-04 | $10585197192.25           | $13284688177.25            | 42.3200%                  | 53.1100%                   |
| 2025-08-05 | $11253210302.20           | $13368625281.50            | 44.4500%                  | 52.8100%                   |
| 2025-08-06 | $10079543682.36           | $13055514010.96            | 40.2700%                  | 52.1600%                   |
| 2025-08-07 | $10986963887.15           | $12948201658.45            | 43.6800%                  | 51.4800%                   |
| 2025-08-08 | $10750069599.06           | $12877019346.46            | 42.6500%                  | 51.0900%                   |
| 2025-08-11 | $10896200347.47           | $12773722195.57            | 43.5500%                  | 51.0500%                   |
| 2025-08-12 | $11494012062.42           | $12643515487.72            | 46.0900%                  | 50.7000%                   |
| 2025-08-13 | $10781165796.28           | $12872185630.38            | 42.7300%                  | 51.0200%                   |
| 2025-08-14 | $11226140718.02           | $12817410756.72            | 44.5900%                  | 50.9100%                   |
| 2025-08-15 | $10926010621.91           | $12944019928.41            | 43.3300%                  | 51.3300%                   |
| 2025-08-18 | $11179839451.06           | $13360108251.26            | 44.2800%                  | 52.9200%                   |
| 2025-08-19 | $11863796635.35           | $13552069998.75            | 46.7300%                  | 53.3800%                   |
| 2025-08-20 | $10714619656.42           | $13491407882.22            | 42.2100%                  | 53.1500%                   |
| 2025-08-21 | $10833091652.55           | $13070671595.05            | 42.5600%                  | 51.3500%                   |
| 2025-08-22 | $10620475665.62           | $12887953640.03            | 41.9100%                  | 50.8500%                   |
| 2025-08-25 | $10946135779.18           | $12849237389.90            | 43.3500%                  | 50.8900%                   |
| 2025-08-26 | $11868437905.44           | $12935627392.31            | 46.9600%                  | 51.1800%                   |
| 2025-08-27 | $11115697958.02           | $13059842040.32            | 43.9800%                  | 51.6800%                   |
| 2025-08-28 | $11462798871.02           | $13393961584.22            | 45.3500%                  | 52.9900%                   |
| 2025-08-29 | $11465324660.06           | $13306558153.54            | 45.3100%                  | 52.5900%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-08-01 | 4.4900%             |
| 2025-08-04 | 4.4900%             |
| 2025-08-05 | 4.4900%             |
| 2025-08-06 | 4.4800%             |
| 2025-08-07 | 4.4800%             |
| 2025-08-08 | 4.4800%             |
| 2025-08-11 | 4.4800%             |
| 2025-08-12 | 4.4800%             |
| 2025-08-13 | 4.4800%             |
| 2025-08-14 | 4.4800%             |
| 2025-08-15 | 4.4800%             |
| 2025-08-18 | 4.4800%             |
| 2025-08-19 | 4.4800%             |
| 2025-08-20 | 4.4800%             |
| 2025-08-21 | 4.4800%             |
| 2025-08-22 | 4.4800%             |
| 2025-08-25 | 4.4800%             |
| 2025-08-26 | 4.4800%             |
| 2025-08-27 | 4.4800%             |
| 2025-08-28 | 4.4900%             |
| 2025-08-29 | 4.4900%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-08-01 | 1.0000                      |
|  |  |
| 2025-08-04 | 1.0001                      |
|  |  |
| 2025-08-05 | 1.0001                      |
|  |  |
| 2025-08-06 | 1.0001                      |
|  |  |
| 2025-08-07 | 1.0001                      |
|  |  |
| 2025-08-08 | 1.0000                      |
|  |  |
| 2025-08-11 | 1.0001                      |
|  |  |
| 2025-08-12 | 1.0001                      |
|  |  |
| 2025-08-13 | 1.0001                      |
|  |  |
| 2025-08-14 | 1.0001                      |
|  |  |
| 2025-08-15 | 1.0000                      |
|  |  |
| 2025-08-18 | 1.0001                      |
|  |  |
| 2025-08-19 | 1.0001                      |
|  |  |
| 2025-08-20 | 1.0001                      |
|  |  |
| 2025-08-21 | 1.0001                      |
|  |  |
| 2025-08-22 | 1.0000                      |
|  |  |
| 2025-08-25 | 1.0001                      |
|  |  |
| 2025-08-26 | 1.0001                      |
|  |  |
| 2025-08-27 | 1.0001                      |
|  |  |
| 2025-08-28 | 1.0001                      |
|  |  |
| 2025-08-29 | 1.0000                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1000000.00

- **Net Assets of Class:** $15002246675.86

- **Number of Shares Outstanding:** 15001397876.9100

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-08-01 | 1.0000          |
|  |  |
| 2025-08-04 | 1.0001          |
|  |  |
| 2025-08-05 | 1.0001          |
|  |  |
| 2025-08-06 | 1.0001          |
|  |  |
| 2025-08-07 | 1.0001          |
|  |  |
| 2025-08-08 | 1.0000          |
|  |  |
| 2025-08-11 | 1.0001          |
|  |  |
| 2025-08-12 | 1.0001          |
|  |  |
| 2025-08-13 | 1.0001          |
|  |  |
| 2025-08-14 | 1.0001          |
|  |  |
| 2025-08-15 | 1.0000          |
|  |  |
| 2025-08-18 | 1.0001          |
|  |  |
| 2025-08-19 | 1.0001          |
|  |  |
| 2025-08-20 | 1.0001          |
|  |  |
| 2025-08-21 | 1.0001          |
|  |  |
| 2025-08-22 | 1.0000          |
|  |  |
| 2025-08-25 | 1.0001          |
|  |  |
| 2025-08-26 | 1.0001          |
|  |  |
| 2025-08-27 | 1.0001          |
|  |  |
| 2025-08-28 | 1.0001          |
|  |  |
| 2025-08-29 | 1.0000          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-08-01 | $195116934.06             | $73530601.49            |
| 2025-08-04 | $80106511.42              | $69903519.11            |
| 2025-08-05 | $70740390.03              | $69147508.89            |
| 2025-08-06 | $85718738.88              | $58151708.58            |
| 2025-08-07 | $127799457.56             | $63022229.17            |
| 2025-08-08 | $178968449.46             | $58801679.39            |
| 2025-08-11 | $72138957.48              | $95368973.84            |
| 2025-08-12 | $83214039.52              | $143271078.94           |
| 2025-08-13 | $90511628.29              | $84046855.45            |
| 2025-08-14 | $75684159.70              | $75171423.97            |
| 2025-08-15 | $76595585.20              | $60660018.51            |
| 2025-08-18 | $87661117.85              | $117039868.19           |
| 2025-08-19 | $72516471.23              | $67432646.05            |
| 2025-08-20 | $95714363.24              | $72593093.48            |
| 2025-08-21 | $76938077.57              | $69487144.58            |
| 2025-08-22 | $95391659.25              | $76339676.93            |
| 2025-08-25 | $127205674.60             | $111600524.08           |
| 2025-08-26 | $120414712.65             | $100801306.93           |
| 2025-08-27 | $117710093.02             | $90953975.93            |
| 2025-08-28 | $87916808.34              | $80256312.83            |
| 2025-08-29 | $94097312.01              | $75341145.08            |

**Total Gross Subscriptions (Month):** $2112161141.36

**Total Gross Redemptions (Month):** $1712921291.42

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-08-01 | 4.3100%           |
| 2025-08-04 | 4.3100%           |
| 2025-08-05 | 4.3100%           |
| 2025-08-06 | 4.3000%           |
| 2025-08-07 | 4.3000%           |
| 2025-08-08 | 4.3000%           |
| 2025-08-11 | 4.3000%           |
| 2025-08-12 | 4.3000%           |
| 2025-08-13 | 4.3000%           |
| 2025-08-14 | 4.3000%           |
| 2025-08-15 | 4.3000%           |
| 2025-08-18 | 4.3000%           |
| 2025-08-19 | 4.3000%           |
| 2025-08-20 | 4.3000%           |
| 2025-08-21 | 4.3000%           |
| 2025-08-22 | 4.3000%           |
| 2025-08-25 | 4.3000%           |
| 2025-08-26 | 4.3000%           |
| 2025-08-27 | 4.3000%           |
| 2025-08-28 | 4.3100%           |
| 2025-08-29 | 4.3100%           |

## 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):** $15059613800.38
- **C.18.a - Value (excl. sponsor support):** $15059613800.38
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-09-02
- **C.12 - Maturity Date (WAL):** 2025-09-02
- **C.13 - Final Legal Maturity Date:** 2025-09-02
- **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:** 2025-09-08

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

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

**Title of Signing Officer:** Vice President