---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-133898"
form_type: "8-K"
ticker: "CBT"
cik: "0000016040"
company_name: "CABOT CORP"
filed_at: "2025-06-03T23:59:59+00:00"
generated_at: "2026-05-20T01:36:36.899298+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Cabot EVP and Reinforcement Materials President Kalkstein to retire; Wood appointed successor

## Summary
- Hobart Kalkstein will retire as EVP and President, Reinforcement Materials, effective Jan 5, 2026; steps down on June 15, 2025.
- Matthew Wood appointed SVP and President, Reinforcement Materials segment, effective June 15, 2025.
- Kalkstein remains in advisory capacity through retirement to ensure smooth transition.
- Transition agreement extends option exercise period to 36 months and provides half salary during 12-month non-compete.

## SEC filing metadata
- accession: 0001193125-25-133898
- form_type: 8-K
- ticker: CBT
- cik: 0000016040
- company_name: CABOT CORP
- filed_at: 2025-06-03T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/16040/000119312525133898/0001193125-25-133898-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/16040/000119312525133898/d32655d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-133898
- JSON: https://secwatch.observer/filing/0001193125-25-133898.json
- Plain text: https://secwatch.observer/filing/0001193125-25-133898.txt

## Key facts
- Executive change
  Matthew Wood was appointed as Senior Vice President and President, Reinforcement Materials Segment at CABOT CORP.
  - Action: appointed
  - Role: Senior Vice President and President, Reinforcement Materials Segment
  source text: The Board has appointed Matthew Wood a Senior Vice President of the Company, and Mr. Wood will succeed Mr. Kalkstein as President, Reinforcement Materials Segment.
  evidence_url: https://www.sec.gov/Archives/edgar/data/16040/000119312525133898/0001193125-25-133898-index.htm
- Executive change
  Hobart C. Kalkstein departed as Executive Vice President and President, Reinforcement Materials Segment at CABOT CORP.
  - Action: stepped down
  - Role: Executive Vice President and President, Reinforcement Materials Segment
  source text: On May 30, 2025, Hobart C. Kalkstein, Executive Vice President and President, Reinforcement Materials Segment of Cabot Corporation (the "Company"), informed the Company’s Board of Directors (the "Board") of his decision to step down from those positions, effective June 15, 2025.
  evidence_url: https://www.sec.gov/Archives/edgar/data/16040/000119312525133898/0001193125-25-133898-index.htm

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