PIMCO CORPORATE & INCOME OPPORTUNITY FUND 8-K

What Happened

• PIMCO Corporate & Income Opportunity Fund filed an 8-K on June 24, 2026, announcing changes to its investment policies. Effective June 24, 2026, the Fund may, as a principal investment strategy, invest in and/or originate loans. Additionally, effective July 24, 2026, the Fund may invest without limitation in defaulted bonds, subject to its other investment policies. A prospectus and statement of additional information supplement describing these changes is attached as Exhibit 99.1.

Key Details

• Filing date: June 24, 2026 (8-K); loan origination permission effective June 24, 2026.
• Defaulted bonds: Fund permitted to invest without limitation in defaulted bonds effective July 24, 2026.
• Disclosure: Supplement to the Fund’s prospectus and statement of additional information is attached as Exhibit 99.1.
• Signature: Report signed by Ryan G. Leshaw, Chief Legal Officer and Secretary, on June 24, 2026.

Why It Matters

• These changes broaden the Fund’s allowable investments and give the manager more flexibility to pursue loans and distressed securities, which can increase potential yield but also raise credit and liquidity risk.
• Investors should review the prospectus supplement (Exhibit 99.1) to understand how the Fund plans to use loans and defaulted bonds in its strategy and to assess any changes in risk profile or portfolio allocation.
• This is a policy change, not a performance report; shareholders may want to monitor future communications for specifics on allocation, risk controls, and how the Fund intends to implement these new authorities.