Comparable stake leader
VANGUARD CAPITAL MANAGEMENT LLC
SEC ownership of Seagate Technology Holdings plc
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001137789.
Disclosed value leader
VANGUARD PORTFOLIO MANAGEMENT LLC
Comparable rows
50/50
Latest evidence
30 Jun 2026
- Public ticker
- STX on Nasdaq
- Parsed ownership sources
-
13D/G, 13F, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
VANGUARD CAPITAL MANAGEMENT LLC
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
VANGUARD CAPITAL MANAGEMENT LLC
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
30 Jun 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001137789
- Issuer location
- Singapore, Singapore
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Seagate Technology Holdings plc (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
VANGUARD CAPITAL MANAGEME...
Disclosed value leader
VANGUARD PORTFOLIO MANAGE...
Comparable rows
50/50
Latest evidence
30 Jun 2026
13D/G
13F
3/4/5
Lead comparable stake: 7.5%
13D/G row: VANGUARD CAPITAL MANAGEMENT LLC
Showing 1-8 of 50 holder rows.
Quick read
VANGUARD CAPITAL MANAGEMENT LLC leads the comparable SEC ownership view at 7.5%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens VANGUARD CAPITAL MANAGEMENT LLC's linked filing trail.
Comparable ownership
Top 5
VANGUARD CAPITAL MANAGEMENT LLC
7.5%
BlackRock, Inc.
6.1%
JPMORGAN CHASE & CO
4%
VANGUARD PORTFOLIO MANAGEMENT LLC
3.6%
Capital Research Global Investors
3.4%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
7.5%
|
$6,393,061,707
16,318,822 shares
|
$0 | 31 Mar 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
6.1%
from 13D/G
|
$5,592,014,773
14,274,083 shares
|
— | 31 Mar 2026 |
| JPMORGAN CHASE & CO |
13F
13D/G
Company
|
4%
from 13D/G
|
$2,413,508,563
6,659,239 shares
|
— | 31 Mar 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
Vanguard Portfolio Management · Company
|
3.6%
|
$7,282,434,153
7,999,686 shares
|
-$2,817,704,395 | 30 Jun 2026 |
| Capital Research Global Investors |
13F
13D/G
Company
|
3.4%
from 13D/G
|
$2,247,162,783
5,736,070 shares
|
— | 31 Mar 2026 |
| Sanders Capital, LLC |
13F
13D/G
Company
|
1.6%
from 13D/G
|
$5,052,607,464
12,897,201 shares
|
— | 31 Mar 2026 |
| Judy Bruner |
3/4/5
Director
|
0.01%
|
$3,226,375
14,314 shares
|
— | 19 Oct 2025 |
| Thomas A. Szlosek |
3/4/5
Director
|
0%
|
$83,580
357 shares
|
— | 25 Oct 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$254,967,812.
Buys
$0
Insiders: 0
Sells
$254,967,812
Insiders: 11
Net
-$254,967,812
Shares: -515,711
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 515,711
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 150,181 | $0 | $127,183,277 | -$127,183,277 |
| 3-6 | 0 | 103,825 | $0 | $53,737,708 | -$53,737,708 |
| 6-9 | 0 | 155,210 | $0 | $50,174,463 | -$50,174,463 |
| 9-12 | 0 | 106,495 | $0 | $23,872,364 | -$23,872,364 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 25 reporting-owner rows connected to Seagate Technology Holdings plc. Open a relationship link for the CIK-to-CIK filing trail.
Rows
25
Largest Forms 3/4/5 holder
ValueAct Holdings, L.P.
Net 12M change
-$254,967,812
Latest report
03 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| ValueAct Holdings, L.P. | Director, Other* | $1,142,150,950 | Mixed | 17 Feb 2022 | ||
| William D. Mosley | CEO, Director | $247,637,335 | -$165,205,490 | -40% | Filing P/S | 03 Aug 2026 |
| Gianluca Romano | Evp & Cfo | $37,725,047 | -$38,318,795 | -50% | Filing P/S | 11 Jun 2026 |
| Stephen J. Luczo | Director | $19,204,985 | Mixed | 04 Mar 2022 | ||
| Prat Bhatt | Director | $11,966,625 | -$929,880 | -7.2% | Filing P/S | 02 Jun 2026 |
| John C. Morris | Evp & Cto | $9,747,903 | -$9,221,732 | -49% | Filing P/S | 03 Aug 2026 |
| Jeffrey D. Nygaard | EVP, Operations and Technology | $8,683,090 | Mixed | 01 Feb 2023 | ||
| Stephanie Tilenius | Director | $8,182,807 | -$1,756,334 | -18% | Filing P/S | 05 May 2026 |
| Richard L. Clemmer | Director | $7,608,125 | Mixed | 25 Oct 2025 | ||
| Shankar Arumugavelu | Director | $6,146,807 | -$2,400,505 | -28% | Filing P/S | 04 Jun 2026 |
| Michael R. Cannon | Director | $4,654,423 | Mixed | 25 Oct 2025 | ||
| Edward J. Zander | Director | $3,894,105 | Mixed | 23 Oct 2023 | ||
| Ban Seng Teh | EVP & Chief Commercial Officer | $3,776,015 | -$28,680,375 | -88% | Filing P/S | 11 Jun 2026 |
| Yolanda Lee Conyers | Director | $3,630,738 | -$1,290,472 | -26% | Filing P/S | 01 Jun 2026 |
| Ravi Naik | EVP, Lyve Storage Services | $3,302,845 | Mixed | 22 Mar 2023 | ||
| Dylan G. Haggart | Director | $3,271,681 | Mixed | 25 Oct 2025 | ||
| Judy Bruner | Director | $3,226,375 | Mixed | 19 Oct 2025 | ||
| Katherine Schuelke | SVP, CLO & Corporate Secretary | $2,470,355 | Mixed | 09 Dec 2023 | ||
| Jeffrey D. Fochtman | SVP, Business & Marketing | $1,252,560 | Mixed | 12 Sep 2022 | ||
| Kian Fatt Chong | EVP Global Operations | $986,451 | -$4,360,949 | -82% | Mixed | 11 Jun 2026 |
Recent insider transactions for Seagate Technology Holdings plc
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| John C. Morris | STX | Ordinary Shares | Sale | -1.39% | $137,384 | $817.76 | -168 | 11,920 | 03 Aug 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -5.46% | $14,130,293 | $827.30 | -17,080 | 295,517 | 03 Aug 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -3.97% | $10,380,838 | $803.47 | -12,920 | 312,597 | 03 Aug 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 4.49% | 14,000 | 325,517 | 03 Aug 2026 | Direct | ||
| William D. Mosley | STX | NQ Options | Options Exercise | -11.2% | -14,000 | 111,100 | 03 Aug 2026 | Direct | ||
| James C. Lee | STX | Ordinary Shares | Sale | -66.7% | $608,950 | $877.45 | -694 | 347 | 30 Jul 2026 | Direct |
| James C. Lee | STX | Ordinary Shares | Sale | -34.7% | $490,741 | $905.01 | -542 | 1,019 | 23 Jul 2026 | Direct |
| James C. Lee | STX | Ordinary Shares | Options Exercise | 381.8% | 1,237 | 1,561 | 22 Jul 2026 | Direct | ||
| James C. Lee | STX | Restricted Share Unit | Options Exercise | -11.1% | -1,237 | 9,902 | 22 Jul 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Sale | -2.91% | $8,636,883 | $924.42 | -9,343 | 311,517 | 01 Jul 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -6.05% | $18,807,775 | $910.48 | -20,657 | 320,860 | 01 Jul 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 4.27% | 14,000 | 341,517 | 01 Jul 2026 | Direct | ||
| William D. Mosley | STX | NQ Options | Options Exercise | -10.1% | -14,000 | 125,100 | 01 Jul 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Sale | -10.1% | $1,200,579 | $880.19 | -1,364 | 12,088 | 12 Jun 2026 | Direct |
| Ban Seng Teh | STX | Ordinary Shares | Sale | -18.7% | $870,508 | $880.19 | -989 | 4,290 | 12 Jun 2026 | Direct |
| Gianluca Romano | STX | Ordinary Shares | Sale | -2.06% | $795,029 | $880.19 | -903 | 42,860 | 12 Jun 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -0.54% | $1,556,394 | $880.19 | -1,768 | 327,517 | 12 Jun 2026 | Direct |
| John C. Morris | STX | Ordinary Shares | Options Exercise | 7.53% | 942 | 13,452 | 11 Jun 2026 | Direct | ||
| John C. Morris | STX | Restricted Share Unit | Options Exercise | -16.7% | -942 | 4,710 | 11 Jun 2026 | Direct | ||
| Ban Seng Teh | STX | Ordinary Shares | Options Exercise | 23% | 989 | 5,279 | 11 Jun 2026 | Direct | ||
| Ban Seng Teh | STX | Restricted Share Unit | Options Exercise | -16.7% | -989 | 4,945 | 11 Jun 2026 | Direct | ||
| Kian Fatt Chong | STX | Ordinary Shares | Options Exercise | 36.8% | 678 | 2,518 | 11 Jun 2026 | Direct | ||
| Kian Fatt Chong | STX | Restricted Share Unit | Options Exercise | -16.7% | -678 | 3,392 | 11 Jun 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Options Exercise | 4.03% | 1,695 | 43,764 | 11 Jun 2026 | Direct | ||
| Gianluca Romano | STX | Restricted Share Unit | Options Exercise | -16.7% | -1,695 | 8,475 | 11 Jun 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 1.02% | 3,319 | 329,285 | 11 Jun 2026 | Direct | ||
| William D. Mosley | STX | Restricted Share Unit | Options Exercise | -16.7% | -3,319 | 16,595 | 11 Jun 2026 | Direct | ||
| Ban Seng Teh | STX | Ordinary Shares | Sale | -13.4% | $544,893 | $821.86 | -663 | 4,290 | 10 Jun 2026 | Direct |
| John C. Morris | STX | Ordinary Shares | Sale | -4.49% | $471,426 | $821.66 | -574 | 12,199 | 10 Jun 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -0.87% | $2,345,874 | $821.74 | -2,855 | 324,870 | 10 Jun 2026 | Direct |
| Gianluca Romano | STX | Ordinary Shares | Sale | -3.16% | $1,109,780 | $821.76 | -1,350 | 41,381 | 10 Jun 2026 | Direct |
| Kian Fatt Chong | STX | Ordinary Shares | Options Exercise | 46.2% | 581 | 1,840 | 09 Jun 2026 | Direct | ||
| Kian Fatt Chong | STX | Restricted Share Unit | Options Exercise | -74.2% | -581 | 202 | 09 Jun 2026 | Direct | ||
| Ban Seng Teh | STX | Ordinary Shares | Options Exercise | 34.2% | 1,262 | 4,953 | 09 Jun 2026 | Direct | ||
| Ban Seng Teh | STX | Restricted Share Unit | Options Exercise | -67.8% | -1,262 | 600 | 09 Jun 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Options Exercise | 9.66% | 1,130 | 12,830 | 09 Jun 2026 | Direct | ||
| John C. Morris | STX | Restricted Share Unit | Options Exercise | -69.3% | -1,130 | 500 | 09 Jun 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 1.62% | 5,230 | 327,285 | 09 Jun 2026 | Direct | ||
| William D. Mosley | STX | Restricted Share Unit | Options Exercise | -65% | -5,230 | 2,815 | 09 Jun 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Options Exercise | 6.12% | 2,474 | 42,896 | 09 Jun 2026 | Direct | ||
| Gianluca Romano | STX | Restricted Share Unit | Options Exercise | -72.1% | -2,474 | 959 | 09 Jun 2026 | Direct | ||
| Shankar Arumugavelu | STX | Ordinary Shares | Sale | -13.1% | $927,680 | $927.68 | -1,000 | 6,626 | 04 Jun 2026 | Direct |
| Prat Bhatt | STX | Ordinary Shares | Sale | -7.21% | $929,880 | $929.88 | -1,000 | 12,869 | 02 Jun 2026 | Direct |
| Yolanda Lee Conyers | STX | Ordinary Shares | Sale | -15.5% | $663,998 | $885.33 | -750 | 4,101 | 01 Jun 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -4.08% | $12,746,389 | $924.99 | -13,780 | 323,591 | 01 Jun 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -4.59% | $14,601,435 | $900.21 | -16,220 | 337,371 | 01 Jun 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 4.12% | 14,000 | 353,591 | 01 Jun 2026 | Direct | ||
| William D. Mosley | STX | NQ Options | Options Exercise | -9.14% | -14,000 | 139,100 | 01 Jun 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Sale | -8.12% | $22,538,568 | $751.29 | -30,000 | 339,591 | 20 May 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 3.94% | 14,000 | 369,591 | 20 May 2026 | Direct |
* marks a reported price that did not pass the local price check.