SCHEDULE 13G/A

Six Flags Entertainment Corp

Common Stock · CUSIP: 83001C108

Event date: 2025-06-30

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Darlington Partners Capital Management, LP

  Shares: 8,700,000.00 · Class: 8.6%

• Darlington Partners GP, LLC

  Shares: 8,700,000.00 · Class: 8.6%

• Darlington Partners, L.P.

  Shares: 8,700,000.00 · Class: 8.6%

• Scott W. Clark

  Shares: 8,700,000.00 · Class: 8.6%

• Ramsey B. Jishi

  Shares: 8,700,000.00 · Class: 8.6%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.