Marathon Petroleum CEO Maryann Mannen Withholds 908 Shares for Taxes

What Happened
Maryann T. Mannen, Chairman of the Board, President and Chief Executive Officer of Marathon Petroleum Corp (MPC), disposed of 908 shares on August 3, 2026 as a tax-withholding payment. The shares were valued at $311.78 each, totaling approximately $283,096. This transaction is a share withholding to satisfy tax obligations (code F), not an open-market sale indicating a trading decision.

Key Details

• Transaction date: 2026-08-03; Form 4 filed: 2026-08-04 (timely).
• Shares withheld/disposed: 908 at $311.78 per share; total ≈ $283,096.
• Transaction code: F — payment of exercise price or tax liability (withholding).
• Shares owned after the transaction: not specified in the provided filing excerpt.
• No indication in the filing of a 10b5-1 plan or an open-market sale; this appears to be routine tax withholding.

Context
Withholding shares to cover taxes is common when executives exercise options or when restricted stock units vest. These disposals are administrative (to satisfy tax obligations) and generally do not convey the same informational value about insider sentiment as voluntary market purchases or sales. Purchases by insiders are typically more notable as potential bullish signals.