# EDGAR Filing Document

**Accession Number:** 0000831114
**File Stem:** 0001398344-25-018853
**Filing Date:** 2025-10
**Character Count:** 9339
**Document Hash:** 06b9f77f5635f43b2b16da6ae059d003
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001398344-25-018853.hdr.sgml**: 20251003

**ACCESSION NUMBER**: 0001398344-25-018853

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 18

**FILED AS OF DATE**: 20251003

**DATE AS OF CHANGE**: 20251003

**EFFECTIVENESS DATE**: 20251003

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** RBB FUND, INC.
- **CENTRAL INDEX KEY:** 0000831114

**ORGANIZATION NAME:**
- **EIN:** 510312196
- **STATE OF INCORPORATION:** MD
- **FISCAL YEAR END:** 0831

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-20827
- **FILM NUMBER:** 251373520

**BUSINESS ADDRESS:**
- **STREET 1:** 615 E. MICHIGAN ST.
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202
- **BUSINESS PHONE:** 609-731-6256

**MAIL ADDRESS:**
- **STREET 1:** 615 E. MICHIGAN ST.
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** RBB FUND INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FUND INC /DE/
- **DATE OF NAME CHANGE:** 19600201

## Series and Classes Contracts Data

### F/m Compoundr High Yield Bond ETF (Series ID: S000094424)

---

|  |  |
|:---|:---|
| Class Name                        | Class ID   |
| F/m Compoundr High Yield Bond ETF | C000262930 |

---

### F/m Compoundr U.S. Aggregate Bond ETF (Series ID: S000094427)

---

|  |  |
|:---|:---|
| Class Name                            | Class ID   |
| F/m Compoundr U.S. Aggregate Bond ETF | C000262933 |

---

## Series and Classes Contracts Data

### F/m Compoundr High Yield Bond ETF (Series ID: S000094424)

| Class ID   | Class Name                        | Ticker Symbol   |
|:---|:---|:---|
| C000262930 | F/m Compoundr High Yield Bond ETF |  |

### F/m Compoundr U.S. Aggregate Bond ETF (Series ID: S000094427)

| Class ID   | Class Name                            | Ticker Symbol   |
|:---|:---|:---|
| C000262933 | F/m Compoundr U.S. Aggregate Bond ETF |  |

?xml version='1.0' encoding='ASCII'?

**THE RBB FUND, INC.**

**F/m Compoundr High Yield Bond ETF** 

**(Ticker: CPHY)**

**F/m Compoundr U.S. Aggregate Bond ETF**

**(Ticker: CPAG)**

**Supplement dated October 3, 2025**

**to the Prospectus and Statement of Additional Information ("SAI"), each dated August 11, 2025**

&nbsp;&nbsp;&nbsp;&nbsp;1. Effective
 as of October 1, 2025 and through December 31, 2026, F/m Investments LLC, the investment
 adviser to the F/m Compoundr High Yield Bond ETF and F/m Compoundr U.S. Aggregate Bond
 ETF (each a "Fund" and together the "Funds"), has contractually
 agreed to waive and/or reimburse certain fees and expenses
 so that the total annual fund operating expenses (excluding Acquired Fund Fees and Expenses
 ("AFFE"), brokerage commissions, extraordinary items, interest or taxes)
 ("annual operating expenses") is limited to 0.25% of each Fund's average
 daily net assets . All references in the Funds' Prospectus and SAI are revised
 accordingly.

&nbsp;&nbsp;&nbsp;&nbsp;2. In
 addition, the "Fees and Expenses" table in the section entitled "Summary
 Section F/m Compoundr High Yield Bond ETF" of the Prospectus is hereby deleted
 and replaced with the following:

**Fees and Expenses**

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund ("Shares"). **You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and Example below.**

**Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):**

---

| | |
|:---|:---|
| Management Fees | 0.49% |
| Distribution (12b-1) Fees |  |
| Acquired Fund Fees and Expenses<sup>(1)</sup> | 0.10% |
| Other Expenses |  |
| Total Annual Fund Operating Expenses | 0.59% |
| Fee Waivers and/or Expense Reimbursement<sup>(2)</sup> | -0.24% |
| Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursement | 0.35% |

---

<sup>(1)</sup> "Acquired Fund Fees and Expenses" ("AFFE") are indirect fees and expenses that the Fund incurs from investing in the shares of other investment companies. Total Annual Fund Operating Expenses do not correlate to the expense ratio in the Fund's Financial Highlights because the Financial Highlights include only the direct operating expenses incurred by the Fund, and exclude AFFE.

<sup>(2)</sup> F/m Investments LLC (the "Adviser") has contractually agreed to waive and/or reimburse certain fees and expenses so that the total annual fund operating expenses (excluding AFFE, brokerage commissions, extraordinary items, interest or taxes) is limited to 0.25% of the Fund's average daily net assets. This contractual limitation is in effect until December 31, 2026, and may not be terminated prior to that date without the approval of the Board of Directors of The RBB Fund, Inc.

*Example*

This Example is intended to help you compare the cost of investing in the F/m Compoundr High Yield Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then hold or redeem all of your Shares at the end of those periods. The Example also assumes that: (1) your investment has a 5% return each year, and (2) the Fund's operating expenses remain the same (taking into account the contractual expense limitation agreement). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

---

| | |
|:---|:---|
| **1 Year** | **3 Years** |
| $36 | $165 |

---

&nbsp;&nbsp;&nbsp;&nbsp;3. The
 "Fees and Expenses" table in the section entitled "Summary Section
 F/m Compoundr U.S. Aggregate Bond ETF" of the Prospectus is hereby deleted and
 replaced with the following:

**Fees and Expenses**

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund ("Shares"). **You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and Example below.**

**Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):**

---

| | |
|:---|:---|
| Management Fees | 0.39% |
| Distribution (12b-1) Fees |  |
| Acquired Fund Fees and Expenses<sup>(1)</sup> | 0.06% |
| Other Expenses |  |
| Total Annual Fund Operating Expenses | 0.45% |
| Fee Waivers and/or Expense Reimbursement<sup>(2)</sup> | -0.14% |
| Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursement | 0.31% |

---

<sup>(1)</sup> "Acquired Fund Fees and Expenses" ("AFFE") are indirect fees and expenses that the Fund incurs from investing in the shares of other investment companies. Total Annual Fund Operating Expenses do not correlate to the expense ratio in the Fund's Financial Highlights because the Financial Highlights include only the direct operating expenses incurred by the Fund, and exclude AFFE.

<sup>(2)</sup> F/m Investments LLC (the "Adviser") has contractually agreed to waive and/or reimburse certain fees and expenses so that the total annual fund operating expenses (excluding AFFE, brokerage commissions, extraordinary items, interest or taxes) is limited to 0.25% of the Fund's average daily net assets. This contractual limitation is in effect until December 31, 2026, and may not be terminated prior to that date without the approval of the Board of Directors of The RBB Fund, Inc.

*Example*

This Example is intended to help you compare the cost of investing in the F/m Compoundr U.S. Aggregate Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then hold or redeem all of your Shares at the end of those periods. The Example also assumes that: (1) your investment has a 5% return each year, and (2) the Fund's operating expenses remain the same (taking into account the contractual expense limitation agreement). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

---

| | |
|:---|:---|
| **1 Year** | **3 Years** |
| $32 | $130 |

---

&nbsp;&nbsp;&nbsp;&nbsp;4. The
 section of the Prospectus entitled "Management of the Funds – Investment
 Adviser" and the section of the SAI entitled "Investment Advisory Agreement
 – Investment Advisory Agreement" are each amended by adding the following:

The Adviser has contractually agreed to waive its advisory fee and/or reimburse expenses in order to limit Total Annual Fund Operating Expenses (excluding certain items discussed below) to 0.25% of average daily net assets of the F/m Compoundr High Yield Fund and F/m Compoundr U.S. Aggregate Fund. In determining the Adviser's obligation to waive advisory fees and/or reimburse expenses, the following expenses are not taken into account and could cause each Fund's net Total Annual Fund Operating Expenses to exceed 0.25%, as applicable: acquired fund fees and expenses, brokerage commissions, extraordinary items, interest or taxes. This contractual limitation is in effect until December 31, 2026, and may not be terminated prior to that date without the approval of the Board of the Company.

**\* \* \* \* \***

**Please retain this supplement for your reference.**