TransDigm Co-COO Exercises and Sells $4.62M in Shares Under 10b5-1 Plan

Executive Summary

On October 16, 2026, TransDigm Group INC ($TDG) filed a Form 4 detailing insider transactions by Co-Chief Operating Officer Joel Reiss. On October 15, 2026, Reiss exercised stock options to acquire 4,100 shares of common stock at an exercise price of $284.97 per share, and simultaneously disposed of all 4,100 shares in the open market through 21 separate tranches. The transactions were conducted pursuant to a pre-arranged Rule 10b5-1 trading plan.

Transaction Breakdown

• Option Exercise (Code M): 4,100 shares acquired at an exercise price of $284.97 per share (total cost: $1,168,377.00).
• Open Market Sales (Code S): 4,100 shares sold at weighted average prices between $1,112.27 and $1,135.95 per share, yielding aggregate gross proceeds of approximately $4,624,943.91.
• Net Realized Value: Approximately $3,456,566.91 before taxes and transaction fees.
• Post-Transaction Holdings: Reiss maintains direct beneficial ownership of 3,600 shares of common stock, leaving his core equity stake unchanged prior to the option exercise.

Trading Significance

The trading significance is assessed as Low. This transaction represents a standard cashless/same-day option exercise and liquidation conducted under an affirmative Rule 10b5-1 trading plan. Because the transactions did not diminish Reiss's base common stock holdings (which remain at 3,600 shares) and were scheduled via an automated plan, they reflect regular executive equity monetization rather than a discretionary shift in sentiment regarding the company's outlook.