Seagate CEO William Mosley Exercises Options and Sells $14.1M in STX Under Rule 10b5-1 Plan

Executive Summary

On November 2, 2026, William D. Mosley, Chief Executive Officer and Director of Seagate Technology Holdings plc (NASDAQ: STX), exercised 14,000 non-qualified stock options at an exercise price of $46.23 per share and sold a total of 23,280 ordinary shares. The gross proceeds from the open-market sales amounted to approximately $14.07 million, executed at weighted-average prices spanning from $587.99 to $616.66 per share.

Transaction Breakdown

• Option Exercise (Code M): Mosley exercised 14,000 NQ options with an expiration date of September 9, 2027, for a total exercise cost of $647,220.
• Open-Market Sales (Code S): Disposed of 23,280 ordinary shares across 27 separate transaction blocks on November 2, 2026.
• Rule 10b5-1 Trading Plan: Footnote 1 indicates that all transactions were executed pursuant to a pre-established Rule 10b5-1 trading plan adopted on February 18, 2026.
• Net Share Impact: Net reduction of 9,280 ordinary shares owned directly (from 362,108.25 to 352,828.25 shares).

Market & Insider Signal Assessment

While the gross value of the transaction exceeds $14 million, the trading significance is rated Medium due to the adoption of a pre-planned Rule 10b5-1 arrangement several months prior. Mosley continues to retain a substantial direct equity interest of over 352,800 ordinary shares in the company, alongside 69,100 derivative options.