Holder evidence
50
SEC ownership of Seagate Technology Holdings plc
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001137789.
Lead holder
VANGUARD CAPITAL MANAGEMENT LLC
13D/G signal
VANGUARD CAPITAL MANAGEMENT LLC
Latest evidence
31 Mar 2026
- CIK
- 0001137789
- Symbol
- STX on Nasdaq
- Location
- Singapore, Singapore
- SEC evidence mix
- 13D/G, 13F, and 3/4/5
- Lead holder
- VANGUARD CAPITAL MANAGEMENT LLC
- Latest large-stake holder
- VANGUARD CAPITAL MANAGEMENT LLC
- Latest evidence date
- 31 Mar 2026
Issuer identity
Ownership snapshot
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.
Lead holder
VANGUARD CAPITAL MANAGEME...
13D/G signal
VANGUARD CAPITAL MANAGEME...
Evidence rows
50
Latest as of
31 Mar 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.
Rank 1 holder
VANGUARD CAPITAL MANAGEMENT LLC
13D/G
13F
- Ownership
- 7.5%
- Position
- $6.39B
Rank 2 holder
BlackRock, Inc.
13F
13D/G
- Ownership
- 6.1%
- Position
- $5.59B
Rank 3 holder
Sanders Capital, LLC
13D/G
13F
- Ownership
- 6%
- Position
- $5.11B
| 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 |
| Sanders Capital, LLC |
13D/G
13F
Company
|
6%
|
$5,106,700,638
13,035,275 shares
|
-$2,298,601,850 | 31 Mar 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
Vanguard Portfolio Management · Company
|
5.1%
|
$4,346,541,158
11,094,908 shares
|
$0 | 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 |
| Capital Research Global Investors |
13F
13D/G
Company
|
3.4%
from 13D/G
|
$2,247,162,783
5,736,070 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: -$200,285,123.
Buys
$0
Insiders: 0
Sells
$200,285,123
Insiders: 11
Net
-$200,285,123
Shares: -700,191
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 700,191
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 143,299 | $0 | $86,431,115 | -$86,431,115 |
| 3-6 | 0 | 92,164 | $0 | $33,086,566 | -$33,086,566 |
| 6-9 | 0 | 173,903 | $0 | $43,232,025 | -$43,232,025 |
| 9-12 | 0 | 290,825 | $0 | $37,535,416 | -$37,535,416 |
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
Lead holder
ValueAct Holdings, L.P.
Net 12M change
-$200,285,122
Latest report
20 May 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 | $259,169,059 | -$103,434,204 | -29% | Filing P/S | 20 May 2026 |
| Gianluca Romano | Evp & Cfo | $31,527,650 | -$36,413,985 | -54% | Filing P/S | 07 May 2026 |
| Stephen J. Luczo | Director | $19,204,985 | Mixed | 04 Mar 2022 | ||
| John C. Morris | Evp & Cto | $8,943,265 | -$7,412,342 | -45% | Filing P/S | 04 May 2026 |
| Jeffrey D. Nygaard | EVP, Operations and Technology | $8,683,090 | Mixed | 01 Feb 2023 | ||
| Stephanie Tilenius | Director | $8,182,807 | -$2,101,136 | -20% | Filing P/S | 05 May 2026 |
| Richard L. Clemmer | Director | $7,608,125 | Mixed | 25 Oct 2025 | ||
| Michael R. Cannon | Director | $4,654,423 | -$2,878,646 | -38% | Mixed | 25 Oct 2025 |
| Edward J. Zander | Director | $3,894,105 | Mixed | 23 Oct 2023 | ||
| 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 | ||
| Prat Bhatt | Director | $3,126,072 | Mixed | 25 Oct 2025 | ||
| Ban Seng Teh | EVP & Chief Commercial Officer | $3,016,595 | -$38,702,820 | -93% | Filing P/S | 13 May 2026 |
| Katherine Schuelke | SVP, CLO & Corporate Secretary | $2,470,355 | Mixed | 09 Dec 2023 | ||
| Shankar Arumugavelu | Director | $2,246,352 | -$1,472,825 | -40% | Filing P/S | 10 Nov 2025 |
| Yolanda Lee Conyers | Director | $1,909,305 | -$714,232 | -27% | Filing P/S | 02 Mar 2026 |
| Jeffrey D. Fochtman | SVP, Business & Marketing | $1,252,560 | Mixed | 12 Sep 2022 | ||
| Robert A. Bruggeworth | Director | $738,983 | Mixed | 19 Oct 2024 |
Recent insider transactions for Seagate Technology Holdings plc
Showing up to 300 most recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | Reported value | Reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| 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 | ||
| William D. Mosley | STX | NQ Options | Options Exercise | -8.38% | -14,000 | 153,100 | 20 May 2026 | Direct | ||
| Ban Seng Teh | STX | Ordinary Shares | Sale | -68.4% | $6,540,725 | $817.28 | -8,003 | 3,691 | 14 May 2026 | Direct |
| Ban Seng Teh | STX | Ordinary Shares | Options Exercise | 216.8% | 8,003 | 11,694 | 14 May 2026 | Direct | ||
| Ban Seng Teh | STX | NQ Options | Options Exercise | -79% | -8,003 | 2,130 | 14 May 2026 | Direct | ||
| Ban Seng Teh | STX | Ordinary Shares | Sale | -67.2% | $6,147,254 | $813.45 | -7,557 | 3,691 | 13 May 2026 | Direct |
| Gianluca Romano | STX | Ordinary Shares | Sale | -4.44% | $1,464,540 | $770.00 | -1,902 | 40,945 | 07 May 2026 | Direct |
| Gianluca Romano | STX | Ordinary Shares | Sale | -34.4% | $17,410,692 | $774.22 | -22,488 | 42,847 | 06 May 2026 | Direct |
| Stephanie Tilenius | STX | Ordinary Shares | Sale | -12.9% | $1,211,250 | $766.61 | -1,580 | 10,664 | 05 May 2026 | Direct |
| John C. Morris | STX | Ordinary Shares | Sale | -32% | $4,154,090 | $738.37 | -5,626 | 11,954 | 04 May 2026 | Direct |
| James C. Lee | STX | Ordinary Shares | Sale | -68.3% | $516,595 | $741.17 | -697 | 324 | 04 May 2026 | Direct |
| James C. Lee | STX | Ordinary Shares | Tax liability | -34.6% | -540 | 1,021 | 22 Apr 2026 | Direct | ||
| James C. Lee | STX | Ordinary Shares | Options Exercise | 381.8% | 1,237 | 1,561 | 22 Apr 2026 | Direct | ||
| James C. Lee | STX | Restricted Share Unit | Options Exercise | -10% | -1,237 | 11,139 | 22 Apr 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Sale | -5.32% | $8,414,638 | $420.73 | -20,000 | 355,591 | 01 Apr 2026 | Direct |
| William D. Mosley | STX | Ordinary Shares | Sale | -6.14% | $10,000,034 | $406.77 | -24,584 | 375,591 | 19 Mar 2026 | Direct |
| John C. Morris | STX | Ordinary Shares | Sale | -0.63% | $42,273 | $377.44 | -112 | 17,580 | 13 Mar 2026 | Direct |
| Ban Seng Teh | STX | Ordinary Shares | Options Exercise | 9.64% | 989 | 11,248 | 11 Mar 2026 | Direct | ||
| Ban Seng Teh | STX | Restricted Share Unit | Options Exercise | -14.3% | -989 | 5,934 | 11 Mar 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Tax liability | -1.28% | -847 | 65,335 | 11 Mar 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Options Exercise | 2.63% | 1,695 | 66,182 | 11 Mar 2026 | Direct | ||
| Gianluca Romano | STX | Restricted Share Unit | Options Exercise | -14.3% | -1,695 | 10,170 | 11 Mar 2026 | Direct | ||
| Kian Fatt Chong | STX | Ordinary Shares | Options Exercise | 116.7% | 678 | 1,259 | 11 Mar 2026 | Direct | ||
| Kian Fatt Chong | STX | Restricted Share Unit | Options Exercise | -14.3% | -678 | 4,070 | 11 Mar 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Tax liability | -2.37% | -430 | 17,692 | 11 Mar 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Options Exercise | 5.48% | 942 | 18,122 | 11 Mar 2026 | Direct | ||
| John C. Morris | STX | Restricted Share Unit | Options Exercise | -14.3% | -942 | 5,652 | 11 Mar 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Tax liability | -0.41% | -1,658 | 400,175 | 11 Mar 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 0.83% | 3,319 | 401,833 | 11 Mar 2026 | Direct | ||
| William D. Mosley | STX | Restricted Share Unit | Options Exercise | -14.3% | -3,319 | 19,914 | 11 Mar 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Tax liability | -2.97% | -516 | 16,837 | 09 Mar 2026 | Direct | ||
| John C. Morris | STX | Ordinary Shares | Options Exercise | 6.92% | 1,130 | 17,468 | 09 Mar 2026 | Direct | ||
| John C. Morris | STX | Restricted Share Unit | Options Exercise | -53.1% | -1,130 | 999 | 09 Mar 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Tax liability | -1.9% | -1,236 | 63,729 | 09 Mar 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Options Exercise | 3.94% | 2,473 | 65,244 | 09 Mar 2026 | Direct | ||
| Gianluca Romano | STX | Restricted Share Unit | Options Exercise | -56.3% | -2,473 | 1,918 | 09 Mar 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Tax liability | -0.65% | -2,613 | 397,306 | 09 Mar 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Options Exercise | 1.33% | 5,230 | 399,721 | 09 Mar 2026 | Direct | ||
| William D. Mosley | STX | Restricted Share Unit | Options Exercise | -48.2% | -5,230 | 5,630 | 09 Mar 2026 | Direct | ||
| Kian Fatt Chong | STX | Ordinary Shares | Options Exercise | 581 | 581 | 09 Mar 2026 | Direct | |||
| Kian Fatt Chong | STX | Restricted Share Unit | Options Exercise | -59% | -581 | 404 | 09 Mar 2026 | Direct | ||
| Ban Seng Teh | STX | Ordinary Shares | Options Exercise | 14% | 1,262 | 10,259 | 09 Mar 2026 | Direct | ||
| Ban Seng Teh | STX | Restricted Share Unit | Options Exercise | -51.3% | -1,262 | 1,199 | 09 Mar 2026 | Direct | ||
| William D. Mosley | STX | Ordinary Shares | Sale | -4.81% | $7,695,262 | $384.76 | -20,000 | 395,897 | 02 Mar 2026 | Direct |
| Yolanda Lee Conyers | STX | Ordinary Shares | Sale | -13.4% | $295,192 | $393.59 | -750 | 4,851 | 02 Mar 2026 | Direct |
| John C. Morris | STX | Ordinary Shares | Sale | -1.43% | $98,400 | $410.00 | -240 | 16,566 | 24 Feb 2026 | Direct |
| Kian Fatt Chong | STX | Ordinary Shares | Sale | -100% | $2,434,740 | $416.48 | -5,846 | 0 | 23 Feb 2026 | Direct |
| Gianluca Romano | STX | Ordinary Shares | Tax liability | -10.1% | -7,096 | 63,250 | 22 Feb 2026 | Direct | ||
| Gianluca Romano | STX | Ordinary Shares | Options Exercise | 24.9% | 14,043 | 70,346 | 22 Feb 2026 | Direct |
* indicates a reported price that failed the local validity check.