WILLIAM D. MOSLEY - 02 Mar 2026 Form 4 Insider Report for Seagate Technology Holdings plc (STX)

Signature
/s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley
Issuer symbol
STX
Transactions as of
02 Mar 2026
Net transactions value
-$7,695,262
Form type
4
Filing time
03 Mar 2026, 18:14:18 UTC
Previous filing
23 Feb 2026
Next filing
11 Mar 2026

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
MOSLEY WILLIAM D CEO, Director SEAGATE TECHNOLOGY HOLDINGS PLC, 47488 KATO ROAD, FREMONT /s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley 03 Mar 2026 0001388390

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction STX Ordinary Shares Sale $328,486 -874 -0.21% $375.84 415,023 02 Mar 2026 Direct F1, F2
transaction STX Ordinary Shares Sale $122,800 -326 -0.08% $376.69 414,697 02 Mar 2026 Direct F3
transaction STX Ordinary Shares Sale $302,359 -800 -0.19% $377.95 413,897 02 Mar 2026 Direct F4
transaction STX Ordinary Shares Sale $659,862 -1,740 -0.42% $379.23 412,157 02 Mar 2026 Direct F5
transaction STX Ordinary Shares Sale $479,331 -1,260 -0.31% $380.42 410,897 02 Mar 2026 Direct F6
transaction STX Ordinary Shares Sale $305,210 -800 -0.19% $381.51 410,097 02 Mar 2026 Direct F7
transaction STX Ordinary Shares Sale $1,338,437 -3,500 -0.85% $382.41 406,597 02 Mar 2026 Direct F8
transaction STX Ordinary Shares Sale $1,035,423 -2,700 -0.66% $383.49 403,897 02 Mar 2026 Direct F9
transaction STX Ordinary Shares Sale $1,038,175 -2,700 -0.67% $384.51 401,197 02 Mar 2026 Direct F10
transaction STX Ordinary Shares Sale $462,467 -1,200 -0.3% $385.39 399,997 02 Mar 2026 Direct F11
transaction STX Ordinary Shares Sale $116,263 -300 -0.08% $387.54 399,697 02 Mar 2026 Direct F12
transaction STX Ordinary Shares Sale $117,005 -300 -0.08% $390.02 399,397 02 Mar 2026 Direct F13
transaction STX Ordinary Shares Sale $196,044 -500 -0.13% $392.09 398,897 02 Mar 2026 Direct F14
transaction STX Ordinary Shares Sale $196,666 -500 -0.13% $393.33 398,397 02 Mar 2026 Direct F15
transaction STX Ordinary Shares Sale $236,851 -600 -0.15% $394.75 397,797 02 Mar 2026 Direct F16
transaction STX Ordinary Shares Sale $317,132 -800 -0.2% $396.42 396,997 02 Mar 2026 Direct F17
transaction STX Ordinary Shares Sale $79,521 -200 -0.05% $397.60 396,797 02 Mar 2026 Direct F18
transaction STX Ordinary Shares Sale $40,027 -100 -0.03% $400.27 396,697 02 Mar 2026 Direct
transaction STX Ordinary Shares Sale $120,627 -300 -0.08% $402.09 396,397 02 Mar 2026 Direct F19
transaction STX Ordinary Shares Sale $40,305 -100 -0.03% $403.05 396,297 02 Mar 2026 Direct
transaction STX Ordinary Shares Sale $121,505 -300 -0.08% $405.02 395,997 02 Mar 2026 Direct F20
transaction STX Ordinary Shares Sale $40,766 -100 -0.03% $407.66 395,897 02 Mar 2026 Direct
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 All transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 20, 2025.
F2 These Ordinary Shares were sold in multiple trades at prices ranging from $375.25 to $376.13. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F3 These Ordinary Shares were sold in multiple trades at prices ranging from $376.37 to $376.91. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F4 These Ordinary Shares were sold in multiple trades at prices ranging from $377.45 to $378.37. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F5 These Ordinary Shares were sold in multiple trades at prices ranging from $378.69 to $379.68. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F6 These Ordinary Shares were sold in multiple trades at prices ranging from $379.89 to $380.83. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F7 These Ordinary Shares were sold in multiple trades at prices ranging from $380.95 to $381.92. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F8 These Ordinary Shares were sold in multiple trades at prices ranging from $381.99 to $382.98. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F9 These Ordinary Shares were sold in multiple trades at prices ranging from $383.05 to $384.00. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F10 These Ordinary Shares were sold in multiple trades at prices ranging from $384.05 to $384.93. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F11 These Ordinary Shares were sold in multiple trades at prices ranging from $385.11 to $386.02. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F12 These Ordinary Shares were sold in multiple trades at prices ranging from $387.35 to $387.64. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F13 These Ordinary Shares were sold in multiple trades at prices ranging from $389.61 to $390.49. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F14 These Ordinary Shares were sold in multiple trades at prices ranging from $391.68 to $392.58. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F15 These Ordinary Shares were sold in multiple trades at prices ranging from $392.95 to $393.73. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F16 These Ordinary Shares were sold in multiple trades at prices ranging from $394.26 to $395.19. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F17 These Ordinary Shares were sold in multiple trades at prices ranging from $395.77 to $396.74. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F18 These Ordinary Shares were sold in multiple trades at prices ranging from $397.51 to $397.70. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F19 These Ordinary Shares were sold in multiple trades at prices ranging from $401.89 to $402.43. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F20 These Ordinary Shares were sold in multiple trades at prices ranging from $404.64 to $405.36. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.