# EDGAR Filing Document

**Accession Number:** 0000946110
**File Stem:** 0001104659-25-095508
**Filing Date:** 2025-10
**Character Count:** 3934
**Document Hash:** 14e24801ef7b966cae26d5a6fc67b8e9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-095508.hdr.sgml**: 20251001

**ACCESSION NUMBER**: 0001104659-25-095508

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251001

**DATE AS OF CHANGE**: 20251001

**EFFECTIVENESS DATE**: 20251001

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** CREDIT SUISSE OPPORTUNITY FUNDS
- **CENTRAL INDEX KEY:** 0000946110

**ORGANIZATION NAME:**
- **EIN:** 133844865
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1031

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-92982
- **FILM NUMBER:** 251363747

**BUSINESS ADDRESS:**
- **STREET 1:** ELEVEN MADISON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010
- **BUSINESS PHONE:** 212-325-2000

**MAIL ADDRESS:**
- **STREET 1:** ELEVEN MADISON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CREDIT SUISSE WARBURG PINCUS OPPORTUNITY FUNDS
- **DATE OF NAME CHANGE:** 20010129

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DLJ OPPORTUNITY FUNDS
- **DATE OF NAME CHANGE:** 20000801

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DLJ WINTHROP OPPORTUNITY FUNDS
- **DATE OF NAME CHANGE:** 19990222

## Series and Classes Contracts Data

### Credit Suisse Strategic Income Fund (Series ID: S000038293)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000118186 | Class A      | CSOAX           |
| C000120097 | Class C      | CSOCX           |
| C000120098 | Class I      | CSOIX           |

**CREDIT SUISSE OPPORTUNITY FUNDS**<br> Credit Suisse Floating Rate High Income Fund<br> Credit Suisse Strategic Income Fund<br> **(each a "Fund" and together, "the Funds")**

**Supplement to the Summary Prospectus and Prospectus of each Fund dated February 28, 2025, as supplemented to date.**

*The section of the Credit Suisse Floating Rate High Income Fund's Summary Prospectus entitled "Performance" and the section of the Funds' Prospectus entitled "Fund Summaries—Credit Suisse Floating Rate High Income Fund—Performance" is supplemented as follows*:

Effective October 1, 2025, the benchmark against which the Fund measures its performance will be changed from the S&P UBS Leveraged Loan Index to the Morningstar LSTA US Leveraged Loan Index. Fund management believes that the new benchmark is more representative of the Fund's strategy.

For the one year, five year and ten year periods ended December 31, 2024, the average annual total returns for the Morningstar LSTA US Leveraged Loan Index were 8.93%, 5.85%, and 5.14%, respectively.

*The section of the Credit Suisse Strategic Income Fund's Summary Prospectus entitled "Performance" and the section of the Funds' Prospectus entitled "Fund Summaries—Credit Suisse Strategic Income Fund—Performance" is supplemented as follows*:

Effective October 1, 2025, the benchmark against which the Fund measures its performance will be changed from the ICE BofA US 3-Month Treasury Bill Index to a blend of 50% Morningstar LSTA US Leveraged Loan Index + 50% ICE BofA US High Yield Constrained Index (the "Customized Reference Benchmark"). Fund management believes that the new benchmark is more representative of the Fund's strategy. In addition, the Fund will also measure its performance against the Bloomberg US Aggregate Bond Index in response to new regulatory requirements.

For the one year, five year and ten year periods ended December 31, 2024, the average annual total returns for Customized Reference Benchmark were 8.59%, 4.98%, and 5.14%, respectively. For the one year, five year and ten year periods ended December 31, 2024, the average annual total returns for the Bloomberg US Aggregate Bond Index were 1.25%, -0.33%, and 1.35%, respectively.

*Shareholders should retain this supplement for future reference.*

Dated: October 1, 2025

16-0925

for

CS-PRO

FRHI-SUMPRO

SIF-SUMPRO

2025-005