# EDGAR Filing Document

**Accession Number:** 0001060517
**File Stem:** 0001410368-25-014064
**Filing Date:** 2025-10
**Character Count:** 13488
**Document Hash:** 4d2a7910f1cd06a60d4ddc6767873479
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-25-014064.hdr.sgml**: 20251007

**ACCESSION NUMBER**: 0001410368-25-014064

**CONFORMED SUBMISSION TYPE**: N-MFP3

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250930

**FILED AS OF DATE**: 20251007

**DATE AS OF CHANGE**: 20251007

**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:** 251379625

**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):** 2025-09-30

**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:** $15034096952.53

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

- **Cash:** $0.00

- **Total Other Assets:** $0.00

- **Total Liabilities:** $53667918.52

- **Net Assets of Series:** $14980429034.01

- **Number of Shares Outstanding (Series):** 14979580235.0500

- **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 (%)   |
|:---|:---|:---|:---|:---|
| 2025-09-02 | $11463287501.93           | $13476584298.28            | 44.5800%                  | 52.4100%                   |
| 2025-09-03 | $10508920611.02           | $13178865370.95            | 41.1500%                  | 51.6000%                   |
| 2025-09-04 | $11160088220.62           | $13118131321.12            | 43.8000%                  | 51.4800%                   |
| 2025-09-05 | $11066261152.34           | $13139343992.34            | 43.1700%                  | 51.2600%                   |
| 2025-09-08 | $11832913560.70           | $13180657307.49            | 46.2400%                  | 51.5100%                   |
| 2025-09-09 | $11976630515.91           | $13029062666.52            | 46.8500%                  | 50.9700%                   |
| 2025-09-10 | $11149196158.40           | $13108206989.60            | 43.6000%                  | 51.2600%                   |
| 2025-09-11 | $11179872263.86           | $13064076717.16            | 43.8000%                  | 51.1800%                   |
| 2025-09-12 | $10991123442.63           | $12991308706.53            | 43.1800%                  | 51.0300%                   |
| 2025-09-15 | $11518077562.21           | $12928838766.41            | 45.3600%                  | 50.9200%                   |
| 2025-09-16 | $12233147936.85           | $12946909144.35            | 48.1400%                  | 50.9500%                   |
| 2025-09-17 | $11758731728.54           | $12937128753.54            | 46.2900%                  | 50.9300%                   |
| 2025-09-18 | $11694352630.83           | $12975640055.03            | 46.0800%                  | 51.1300%                   |
| 2025-09-19 | $11126903614.31           | $12957874815.51            | 43.8700%                  | 51.0900%                   |
| 2025-09-22 | $11328121089.49           | $13074551311.89            | 44.6800%                  | 51.5700%                   |
| 2025-09-23 | $11498831446.90           | $12880310695.90            | 45.4700%                  | 50.9300%                   |
| 2025-09-24 | $11248187594.43           | $12893432872.23            | 44.4800%                  | 50.9900%                   |
| 2025-09-25 | $11556486752.73           | $12816829094.03            | 45.8400%                  | 50.8400%                   |
| 2025-09-26 | $11530796069.20           | $12783211292.50            | 45.9100%                  | 50.9000%                   |
| 2025-09-29 | $12106069655.67           | $12863804128.77            | 48.2900%                  | 51.3100%                   |
| 2025-09-30 | $11943993066.70           | $13059409620.50            | 47.6000%                  | 52.0400%                   |

### 7-Day Gross Yield
| Date       | 7-Day Gross Yield   |
|:---|:---|
| 2025-09-02 | 4.4800%             |
| 2025-09-03 | 4.4800%             |
| 2025-09-04 | 4.4900%             |
| 2025-09-05 | 4.5000%             |
| 2025-09-08 | 4.5000%             |
| 2025-09-09 | 4.5000%             |
| 2025-09-10 | 4.5000%             |
| 2025-09-11 | 4.5000%             |
| 2025-09-12 | 4.4900%             |
| 2025-09-15 | 4.5000%             |
| 2025-09-16 | 4.5000%             |
| 2025-09-17 | 4.5000%             |
| 2025-09-18 | 4.4800%             |
| 2025-09-19 | 4.4000%             |
| 2025-09-22 | 4.3700%             |
| 2025-09-23 | 4.3400%             |
| 2025-09-24 | 4.3100%             |
| 2025-09-25 | 4.3100%             |
| 2025-09-26 | 4.3000%             |
| 2025-09-29 | 4.3100%             |
| 2025-09-30 | 4.3100%             |

### Daily Net Asset Value per Share (Series)
| Date       | Net Asset Value per Share   |
|:---|:---|
| 2025-09-02 | 1.0001                      |
|  |  |
| 2025-09-03 | 1.0001                      |
|  |  |
| 2025-09-04 | 1.0001                      |
|  |  |
| 2025-09-05 | 1.0001                      |
|  |  |
| 2025-09-08 | 1.0001                      |
|  |  |
| 2025-09-09 | 1.0001                      |
|  |  |
| 2025-09-10 | 1.0001                      |
|  |  |
| 2025-09-11 | 1.0002                      |
|  |  |
| 2025-09-12 | 1.0001                      |
|  |  |
| 2025-09-15 | 1.0002                      |
|  |  |
| 2025-09-16 | 1.0002                      |
|  |  |
| 2025-09-17 | 1.0002                      |
|  |  |
| 2025-09-18 | 1.0002                      |
|  |  |
| 2025-09-19 | 1.0001                      |
|  |  |
| 2025-09-22 | 1.0002                      |
|  |  |
| 2025-09-23 | 1.0002                      |
|  |  |
| 2025-09-24 | 1.0002                      |
|  |  |
| 2025-09-25 | 1.0002                      |
|  |  |
| 2025-09-26 | 1.0001                      |
|  |  |
| 2025-09-29 | 1.0001                      |
|  |  |
| 2025-09-30 | 1.0002                      |
|  |  |

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

### Class: Single Class

- **Minimum Initial Investment:** $1000000.00

- **Net Assets of Class:** $14980429034.01

- **Number of Shares Outstanding:** 14979580235.0500

**Daily Net Asset Value per Share (Class)**
| Date       | NAV per Share   |
|:---|:---|
| 2025-09-02 | 1.0001          |
|  |  |
| 2025-09-03 | 1.0001          |
|  |  |
| 2025-09-04 | 1.0001          |
|  |  |
| 2025-09-05 | 1.0001          |
|  |  |
| 2025-09-08 | 1.0001          |
|  |  |
| 2025-09-09 | 1.0001          |
|  |  |
| 2025-09-10 | 1.0001          |
|  |  |
| 2025-09-11 | 1.0002          |
|  |  |
| 2025-09-12 | 1.0001          |
|  |  |
| 2025-09-15 | 1.0002          |
|  |  |
| 2025-09-16 | 1.0002          |
|  |  |
| 2025-09-17 | 1.0002          |
|  |  |
| 2025-09-18 | 1.0002          |
|  |  |
| 2025-09-19 | 1.0001          |
|  |  |
| 2025-09-22 | 1.0002          |
|  |  |
| 2025-09-23 | 1.0002          |
|  |  |
| 2025-09-24 | 1.0002          |
|  |  |
| 2025-09-25 | 1.0002          |
|  |  |
| 2025-09-26 | 1.0001          |
|  |  |
| 2025-09-29 | 1.0001          |
|  |  |
| 2025-09-30 | 1.0002          |
|  |  |

**Daily Shareholder Flows**
| Date       | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| 2025-09-02 | $150476242.07             | $85286159.23            |
| 2025-09-03 | $168980617.59             | $77457604.33            |
| 2025-09-04 | $95611931.66              | $57046761.11            |
| 2025-09-05 | $169718320.07             | $146680410.40           |
| 2025-09-08 | $86243008.52              | $85036272.86            |
| 2025-09-09 | $84683903.40              | $78461246.13            |
| 2025-09-10 | $80504358.08              | $69557023.92            |
| 2025-09-11 | $93422364.88              | $121841863.93           |
| 2025-09-12 | $100528835.46             | $137060744.50           |
| 2025-09-15 | $62069595.36              | $87543039.17            |
| 2025-09-16 | $96218162.00              | $82382986.31            |
| 2025-09-17 | $74049071.71              | $76473946.25            |
| 2025-09-18 | $82908692.90              | $73943422.79            |
| 2025-09-19 | $66444042.00              | $88258576.27            |
| 2025-09-22 | $76150755.84              | $90849585.59            |
| 2025-09-23 | $68494935.99              | $97895135.28            |
| 2025-09-24 | $118888533.81             | $130613206.83           |
| 2025-09-25 | $69151683.25              | $101410584.68           |
| 2025-09-26 | $74158714.23              | $169542987.62           |
| 2025-09-29 | $59996074.40              | $85538436.81            |
| 2025-09-30 | $114689065.15             | $72326556.22            |

**Total Gross Subscriptions (Month):** $1993388908.37

**Total Gross Redemptions (Month):** $2015206550.23

**7-Day Net Yield (Class)**
| Date       | 7-Day Net Yield   |
|:---|:---|
| 2025-09-02 | 4.3000%           |
| 2025-09-03 | 4.3000%           |
| 2025-09-04 | 4.3100%           |
| 2025-09-05 | 4.3200%           |
| 2025-09-08 | 4.3200%           |
| 2025-09-09 | 4.3200%           |
| 2025-09-10 | 4.3200%           |
| 2025-09-11 | 4.3200%           |
| 2025-09-12 | 4.3100%           |
| 2025-09-15 | 4.3200%           |
| 2025-09-16 | 4.3200%           |
| 2025-09-17 | 4.3200%           |
| 2025-09-18 | 4.3000%           |
| 2025-09-19 | 4.2200%           |
| 2025-09-22 | 4.1900%           |
| 2025-09-23 | 4.1600%           |
| 2025-09-24 | 4.1300%           |
| 2025-09-25 | 4.1200%           |
| 2025-09-26 | 4.1200%           |
| 2025-09-29 | 4.1300%           |
| 2025-09-30 | 4.1300%           |

## 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):** $15034096952.53
- **C.18.a - Value (excl. sponsor support):** $15034096952.53
- **C.19 - Percentage of Net Assets:** 100.0000%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2025-10-01
- **C.12 - Maturity Date (WAL):** 2025-10-01
- **C.13 - Final Legal Maturity Date:** 2025-10-01
- **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:** 2025-10-07

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

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

**Title of Signing Officer:** Vice President