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
BlackRock, Inc.
Comparable rows
7/50
Latest evidence
30 Sep 2026
- Public ticker
- STX on Nasdaq
- Parsed ownership sources
-
13F, 13D/G, 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
-
7 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 Sep 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
BlackRock, Inc.
Comparable rows
7/50
Latest evidence
30 Sep 2026
13F
13D/G
3/4/5
Lead comparable stake: 7.5%
43 rows are not safely comparable across share classes.
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%.
7 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%
FMR LLC
5.1%
JPMORGAN CHASE & CO
4%
VANGUARD PORTFOLIO MANAGEMENT LLC
3.6%
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 |
13F
13D/G
Company · Vanguard Capital Management
|
7.5%
Reported 13D/G
· 31 Mar 2026
|
$14,118,014,655
14,630,067 shares
|
— | 30 Jun 2026 |
| BlackRock, Inc. |
13F
13D/G
Company
|
6.1%
Reported 13D/G
· 31 Mar 2025
|
$14,635,954,522
15,166,793 shares
|
— | 30 Jun 2026 |
| FMR LLC |
13D/G
13F
Company
|
5.1%
Reported 13D/G
· 30 Sep 2026
|
$8,878,935,152
11,459,204 shares
|
$0 | 30 Sep 2026 |
| JPMORGAN CHASE & CO |
13F
13D/G
Company
|
4%
Reported 13D/G
· 31 Oct 2025
|
$5,037,427,733
5,201,103 shares
|
— | 30 Jun 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13F
13D/G
Company · Vanguard Portfolio Management
|
3.6%
Reported 13D/G
· 30 Jun 2026
|
$7,719,696,990
7,999,686 shares
|
— | 30 Jun 2026 |
| Capital Research Global Investors |
13F
13D/G
Company
|
3.4%
Reported 13D/G
· 30 Jun 2025
|
$4,175,343,665
4,326,781 shares
|
— | 30 Jun 2026 |
| Sanders Capital, LLC |
13F
13D/G
Company
|
1.6%
Reported 13D/G
· 30 Jun 2026
|
$3,365,166,335
3,487,219 shares
|
— | 30 Jun 2026 |
| STATE STREET CORP |
13F
Company
|
—
denominator unverified
|
$9,571,909,059
9,911,669 shares
|
— | 30 Jun 2026 |
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: -$604,979,364.
Buys
$0
Insiders: 0
Sells
$604,979,364
Insiders: 11
Net
-$604,979,364
Shares: -878,534
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 878,534
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 447,108 | $0 | $356,049,825 | -$356,049,825 |
| 3-6 | 0 | 172,392 | $0 | $145,017,369 | -$145,017,369 |
| 6-9 | 0 | 103,825 | $0 | $53,737,708 | -$53,737,708 |
| 9-12 | 0 | 155,210 | $0 | $50,174,463 | -$50,174,463 |
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
-$604.98M
Full value: -$604,979,363 · USD · 12-month changeLatest report
02 Nov 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 | $223,042,539 | -$316,848,086 | -59% | Filing P/S | 02 Nov 2026 |
| Gianluca Romano | Evp & Cfo | $54,635,147 | -$146,392,065 | -73% | Filing P/S | 14 Sep 2026 |
| Richard L. Clemmer | Director | $32,070,683 | Median | 24 Oct 2026 | ||
| Kian Fatt Chong | EVP Global Operations | $24,214,745 | -$2,434,740 | -9.1% | Mixed | 14 Sep 2026 |
| Michael R. Cannon | Director | $20,054,437 | Median | 24 Oct 2026 | ||
| Stephen J. Luczo | Director | $19,204,985 | Mixed | 04 Mar 2022 | ||
| Dylan G. Haggart | Director | $14,494,573 | Median | 24 Oct 2026 | ||
| John C. Morris | Evp & Cto | $14,201,954 | -$32,331,141 | -69% | Filing P/S | 30 Oct 2026 |
| Prat Bhatt | Director | $12,976,401 | -$929,880 | -6.7% | Median | 24 Oct 2026 |
| Stephanie Tilenius | Director | $10,942,641 | -$1,211,250 | -10% | Median | 24 Oct 2026 |
| Jeffrey D. Nygaard | EVP, Operations and Technology | $8,683,090 | Mixed | 01 Feb 2023 | ||
| Shankar Arumugavelu | Director | $7,218,232 | -$2,400,505 | -25% | Median | 24 Oct 2026 |
| Ban Seng Teh | EVP & Chief Commercial Officer | $4,650,730 | -$87,328,853 | -95% | Filing P/S | 14 Sep 2026 |
| Yolanda Lee Conyers | Director | $4,197,569 | -$1,775,205 | -30% | Median | 24 Oct 2026 |
| Edward J. Zander | Director | $3,894,105 | Mixed | 23 Oct 2023 | ||
| Ravi Naik | EVP, Lyve Storage Services | $3,302,845 | Mixed | 22 Mar 2023 | ||
| Judy Bruner | Director | $3,226,375 | Mixed | 19 Oct 2025 | ||
| Mark W. Adams | Director | $2,993,915 | Median | 24 Oct 2026 | ||
| Katherine Schuelke | SVP, CLO & Corporate Secretary | $2,470,355 | Mixed | 09 Dec 2023 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
| William D. Mosley | STX | Ordinary Shares | Sale | -1.9% | -$4,185,349 | $622.82 | -6,720 | 346,108 | 02 Nov 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -6.19% | -$14,024,766 | $602.44 | -23,280 | 352,828 | 02 Nov 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 3.87% | 14,000 | 376,108 | 02 Nov 2026 | Direct | ||
| William D. Mosley | STX | NQ Options | Options Exercise | -16.8% | -14,000 | 69,100 | 02 Nov 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Sale | -11.3% | -$1,739,149 | $650.15 | -2,675 | 20,933 | 30 Oct 2026 | Direct |
| John C. Morris | STX | Ordinary Shares | Options Exercise | 4.03% | 915 | 23,608 | 30 Oct 2026 | Direct | ||
| John C. Morris | STX | NQ Stock Option | Options Exercise | -5.27% | -915 | 16,463 | 30 Oct 2026 | Direct | ||
| Stephanie Tilenius | STX | Ordinary Shares | Tax liability | -3.1% | -380 | 11,864 | 24 Oct 2026 | Direct | ||
| Stephanie Tilenius | STX | Ordinary Shares | Options Exercise | 14.8% | 1,580 | 12,244 | 24 Oct 2026 | Direct | ||
| Stephanie Tilenius | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Stephanie Tilenius | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Thomas A. Szlosek | STX | Ordinary Shares | Tax liability | -19.6% | -380 | 1,558 | 24 Oct 2026 | Direct | ||
| Thomas A. Szlosek | STX | Ordinary Shares | Options Exercise | 440.9% | 1,580 | 1,938 | 24 Oct 2026 | Direct | ||
| Thomas A. Szlosek | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Thomas A. Szlosek | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Dylan G. Haggart | STX | Ordinary Shares | Tax liability | -2.36% | -380 | 15,715 | 24 Oct 2026 | Direct | ||
| Dylan G. Haggart | STX | Ordinary Shares | Options Exercise | 10.9% | 1,580 | 16,095 | 24 Oct 2026 | Direct | ||
| Dylan G. Haggart | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Dylan G. Haggart | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Jay L. Geldmacher | STX | Ordinary Shares | Tax liability | -21.1% | -380 | 1,423 | 24 Oct 2026 | Direct | ||
| Jay L. Geldmacher | STX | Ordinary Shares | Options Exercise | 708.5% | 1,580 | 1,803 | 24 Oct 2026 | Direct | ||
| Jay L. Geldmacher | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Jay L. Geldmacher | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Yolanda Lee Conyers | STX | Ordinary Shares | Tax liability | -7.71% | -380 | 4,551 | 24 Oct 2026 | Direct | ||
| Yolanda Lee Conyers | STX | Ordinary Shares | Options Exercise | 47.2% | 1,580 | 4,931 | 24 Oct 2026 | Direct | ||
| Yolanda Lee Conyers | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Yolanda Lee Conyers | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Richard L. Clemmer | STX | Ordinary Shares | Tax liability | -1.21% | -380 | 30,904 | 24 Oct 2026 | Direct | ||
| Richard L. Clemmer | STX | Ordinary Shares | Options Exercise | 5.32% | 1,580 | 31,284 | 24 Oct 2026 | Direct | ||
| Richard L. Clemmer | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Richard L. Clemmer | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Michael R. Cannon | STX | Ordinary Shares | Tax liability | -2.93% | -449 | 14,858 | 24 Oct 2026 | Direct | ||
| Michael R. Cannon | STX | Ordinary Shares | Options Exercise | 13.9% | 1,868 | 15,307 | 24 Oct 2026 | Direct | ||
| Michael R. Cannon | STX | Restricted Share Unit | Options Exercise | -100% | -1,868 | 0 | 24 Oct 2026 | Direct | ||
| Prat Bhatt | STX | Ordinary Shares | Tax liability | -2.63% | -380 | 14,069 | 24 Oct 2026 | Direct | ||
| Prat Bhatt | STX | Ordinary Shares | Options Exercise | 12.3% | 1,580 | 14,449 | 24 Oct 2026 | Direct | ||
| Prat Bhatt | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Prat Bhatt | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Shankar Arumugavelu | STX | Ordinary Shares | Tax liability | -4.63% | -380 | 7,826 | 24 Oct 2026 | Direct | ||
| Shankar Arumugavelu | STX | Ordinary Shares | Options Exercise | 23.8% | 1,580 | 8,206 | 24 Oct 2026 | Direct | ||
| Shankar Arumugavelu | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| Mark W. Adams | STX | Ordinary Shares | Tax liability | -10.5% | -380 | 3,246 | 24 Oct 2026 | Direct | ||
| Mark W. Adams | STX | Ordinary Shares | Options Exercise | 77.2% | 1,580 | 3,626 | 24 Oct 2026 | Direct | ||
| Mark W. Adams | STX | Restricted Share Unit | Award | 345 | 345 | 24 Oct 2026 | Direct | |||
| Mark W. Adams | STX | Restricted Share Unit | Options Exercise | -100% | -1,580 | 0 | 24 Oct 2026 | Direct | ||
| James C. Lee | STX | Ordinary Shares | Sale | -34.6% | -$351,411 | $642.14 | -547 | 1,037 | 23 Oct 2026 | Direct |
| James C. Lee | STX | Ordinary Shares | Options Exercise | 356.5% | 1,237 | 1,584 | 22 Oct 2026 | Direct | ||
| James C. Lee | STX | Restricted Share Unit | Options Exercise | -12.5% | -1,237 | 8,665 | 22 Oct 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Sale | -2.95% | -$10,293,464 | $935.60 | -11,002 | 362,108 | 01 Oct 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -4.85% | -$17,376,988 | $914.67 | -18,998 | 373,110 | 01 Oct 2026 | Direct |
* marks a reported price that did not pass the local price check.