---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-428038"
form_type: "8-K"
ticker: "MAT"
cik: "0000063276"
company_name: "MATTEL INC /DE/"
filed_at: "2026-10-21T21:57:58+00:00"
generated_at: "2026-10-22T10:06:32.358802+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# Mattel adds EdgePoint partner Lee Matheson to board under cooperation pact; board grows to 10

## Summary
- EdgePoint Investment Group, an approximately 18% Mattel stockholder, signed a cooperation agreement dated October 21, 2026; EdgePoint Partner Lee Matheson joins the board.
- Board expanded from nine to ten directors; Matheson's term expires at the 2027 annual meeting, and Mattel agreed to nominate him for re-election there.
- EdgePoint received director replacement rights: the parties will jointly pick a mutually acceptable successor if Matheson leaves before the 2028 annual meeting.
- Mattel's appointment and nomination obligations terminate if EdgePoint's stake drops below 10% of outstanding common stock.
- Pact runs until five business days after the later of the day after the 2027 annual meeting and Matheson's board departure; includes standstill, voting and confidentiality terms.

## SEC filing metadata
- accession: 0001193125-26-428038
- form_type: 8-K
- ticker: MAT
- cik: 0000063276
- company_name: MATTEL INC /DE/
- filed_at: 2026-10-21T21:57:58+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 1.01, 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/63276/000119312526428038/0001193125-26-428038-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/63276/000119312526428038/d111363d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-428038
- JSON: https://secwatch.observer/filing/0001193125-26-428038.json
- Plain text: https://secwatch.observer/filing/0001193125-26-428038.txt

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