=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-02-05
10b5-1 Pre-arranged Plan: Yes
--- Issuer ---
Name: WESTERN DIGITAL CORP (WDC)
CIK: 0000106040
--- Reporting Owner ---
Name: MASSENGILL MATTHEW E
CIK: 0001232826
Role: Director
--- Non-Derivative Transactions ---
[Transaction #1]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -2,600 | Price: $256.63
Total Value: $667,241.12
Shares Owned After: 34,326 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F2] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $256.12 to a high of $257.09. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #2]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -4,411 | Price: $257.69
Total Value: $1,136,648.98
Shares Owned After: 29,915 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F3] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $257.14 to a high of $258.13. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #3]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -7,000 | Price: $258.67
Total Value: $1,810,703.30
Shares Owned After: 22,915 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F4] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $258.14 to a high of $259.13. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #4]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -4,915 | Price: $259.59
Total Value: $1,275,896.15
Shares Owned After: 18,000 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F5] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $259.15 to a high of $260.12. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #5]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -5,987 | Price: $260.57
Total Value: $1,560,036.78
Shares Owned After: 12,013 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F6] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $260.15 to a high of $261.05. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #6]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -3,597 | Price: $261.71
Total Value: $941,362.60
Shares Owned After: 8,416 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F7] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $261.19 to a high of $262.18. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #7]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -2,300 | Price: $262.77
Total Value: $604,365.94
Shares Owned After: 6,116 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F8] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $262.21 to a high of $263.14. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #8]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -2,600 | Price: $264.01
Total Value: $686,429.12
Shares Owned After: 3,516 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F9] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $263.40 to a high of $264.38. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #9]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -2,200 | Price: $264.99
Total Value: $582,979.76
Shares Owned After: 1,316 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F10] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $264.54 to a high of $265.51. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #10]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -916 | Price: $265.92
Total Value: $243,580.16
Shares Owned After: 400 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F11] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $265.57 to a high of $266.27. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
[Transaction #11]
Security: Common Stock
Date: 2026-02-05 | Code: S (Open market sale)
Shares: -400 | Price: $268.06
Total Value: $107,222.00
Shares Owned After: 0 | Ownership: I (Indirect) | Nature: By Family Trust
Footnotes:
[F1] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
[F12] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $267.58 to a high of $268.53. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
--- Holdings ---
[Holding #1]
Security: Common Stock
Ownership: D (Direct)
[Holding #2]
Security: Common Stock
Ownership: I (Indirect)
--- Footnotes (Complete Index) ---
F1: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 6, 2025.
F10: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $264.54 to a high of $265.51. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F11: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $265.57 to a high of $266.27. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F12: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $267.58 to a high of $268.53. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F2: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $256.12 to a high of $257.09. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F3: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $257.14 to a high of $258.13. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F4: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $258.14 to a high of $259.13. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F5: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $259.15 to a high of $260.12. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F6: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $260.15 to a high of $261.05. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F7: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $261.19 to a high of $262.18. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F8: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $262.21 to a high of $263.14. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
F9: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $263.40 to a high of $264.38. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
--- Signature ---
/s/ By: /s/ Sandra Garcia Attorney-in-Fact For: Matthew E. Massengill (2026-02-06)
