Western Digital CLO Cynthia Tregillis Sells 432 Shares Under 10b5-1 Plan

Insider Transaction Overview

On September 4, 2026, Cynthia L. Tregillis, Chief Legal Officer and Corporate Secretary of Western Digital Corp ($WDC), executed an open-market sale of 432 shares of Common Stock at an average price of $451.20 per share, generating total gross proceeds of approximately $194,918.40.

Key Transaction Details

1. Derivative Settlement & Tax Withholding (Sept 3, 2026):

   • Converted 7.0583 Dividend Equivalent Rights into 7 shares of Common Stock (Code M).
   • Surrendered 700 shares at $441.57 per share ($309,099 total) to satisfy tax withholding obligations incident to RSU vesting (Code F).

2. Open Market Sale (Sept 4, 2026):

   • Sold 432 shares at $451.20 per share (Code S).
   • The sale was executed pursuant to a pre-arranged Rule 10b5-1 trading plan adopted on March 6, 2026.

3. Post-Transaction Holdings:

   • Direct ownership following these transactions stands at 111,030 shares of common stock.

Significance

This filing represents low trading significance as the open-market sale accounts for less than 0.5% of the insider's total equity holdings and was conducted automatically under a Rule 10b5-1 trading plan established six months prior.