---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-242513"
form_type: "8-K"
ticker: "FUN"
cik: "0001999001"
company_name: "Six Flags Entertainment Corporation/NEW"
filed_at: "2025-10-17T23:59:59+00:00"
generated_at: "2026-05-17T03:27:39.797348+00:00"
event_type: "leadership"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Six Flags appoints Sachem Head partner Brudnick to board in cooperation deal

## Summary
- Jonathan Brudnick, a Sachem Head partner, joins Six Flags Board as Class III director effective Oct 17, 2025.
- Board expands to 13 directors (11 independent), will shrink to 11 after Bassoul and Hanrahan depart Dec 31.
- Cooperation agreement imposes standstill, voting commitments; Brudnick must resign if Sachem Head falls below 3% ownership.
- Brudnick appointed to Nominating and Governance Committee with term through 2027 annual meeting.

## SEC filing metadata
- accession: 0001193125-25-242513
- form_type: 8-K
- ticker: FUN
- cik: 0001999001
- company_name: Six Flags Entertainment Corporation/NEW
- filed_at: 2025-10-17T23:59:59+00:00
- event_type: leadership
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 1.01, 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1999001/000119312525242513/0001193125-25-242513-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1999001/000119312525242513/d32756d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-242513
- JSON: https://secwatch.observer/filing/0001193125-25-242513.json
- Plain text: https://secwatch.observer/filing/0001193125-25-242513.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.