VANGUARD GROUP INC
Rank #1
12.5%
- Shares
- 28.12M
- Change
- -20.86K
- Change %
- -7.00%
- Filing
- Dec 31, 2025
Decreased
Methodology published · Market data, model notes, and corrections process are public · Data policy · Corrections policy
NASDAQ · TECHNOLOGY · Holders
Seagate Technology PLC (STX) Institutional Ownership & Insider Trading History
Top STX institutional shareholders, filing changes, and Form 4 insider activity with filters for buys, sales, option exercises, gifts, and tax withholding.
Ownership read
STX insider sentiment: Net selling.
VANGUARD GROUP INC is the largest loaded institutional holder. 115 sale rows and 0 purchase rows are visible in the loaded Form 4 history. Use the filters below to separate real buying and selling from option exercises, gifts, awards, and tax withholding.
Insider flow
STX
Purchases—
Sales119.73K
Directional bars ignore awards, gifts, conversions, and tax withholding rows.
Top holder
28.12M
VANGUARD GROUP INC
Insider stance
Net selling
$67.92M sold / — bought
Latest filing
May 20, 2026
Most recent holder or insider filing date
Rows loaded
240
120 holder / 120 insider
- Holder rows
- 120
- Market data feed
- Latest filing
- May 20, 2026
- Most recent holder or insider filing date
- Increased / initiated
- 61
- 57 decreased in loaded rows
- Insider rows
- 120
- Market data feed
Top 120 institutional holders
Seagate Technology PLC (STX) institutional ownership
Ranked by reported share count, with position changes and latest filing dates where the ownership feed supplies them.
BLACKROCK
Rank #2
6.34%
- Shares
- 14.27M
- Change
- -1.84M
- Change %
- -11.43%
- Filing
- Mar 31, 2026
Decreased
VANGUARD CAPITAL MANAGEMENT LLC
Rank #3
6.28%
- Shares
- 14.16M
- Change
- +14.16M
- Change %
- —
- Filing
- Mar 31, 2026
Initiated
SANDERS CAPITAL
Rank #4
5.72%
- Shares
- 12.90M
- Change
- -4.28M
- Change %
- -24.93%
- Filing
- Mar 31, 2026
Decreased
VANGUARD PORTFOLIO MANAGEMENT LLC
Rank #5
4.92%
- Shares
- 11.09M
- Change
- +11.09M
- Change %
- —
- Filing
- Mar 31, 2026
Initiated
STATE STREET CORP
Rank #6
4.14%
- Shares
- 9.32M
- Change
- -49.17K
- Change %
- -53.00%
- Filing
- Mar 31, 2026
Decreased
FMR LLC
Rank #7
3.63%
- Shares
- 8.18M
- Change
- +4.42M
- Change %
- +1.17%
- Filing
- Mar 31, 2026
Increased
JPMORGAN CHASE & CO
Rank #8
2.96%
- Shares
- 6.66M
- Change
- -338.74K
- Change %
- -4.84%
- Filing
- Mar 31, 2026
Decreased
CAPITAL RESEARCH GLOBAL INVESTORS
Rank #9
2.55%
- Shares
- 5.74M
- Change
- +1.22M
- Change %
- +27.13%
- Filing
- Mar 31, 2026
Increased
GEODE CAPITAL MANAGEMENT
Rank #10
2.25%
- Shares
- 5.06M
- Change
- +164.01K
- Change %
- +3.35%
- Filing
- Mar 31, 2026
Increased
MORGAN STANLEY
Rank #11
2.11%
- Shares
- 4.76M
- Change
- -558.20K
- Change %
- -10.50%
- Filing
- Mar 31, 2026
Decreased
WCM INVESTMENT MANAGEMENT
Rank #12
1.93%
- Shares
- 4.35M
- Change
- -808.02K
- Change %
- -15.68%
- Filing
- Mar 31, 2026
Decreased
DZ BANK AG DEUTSCHE ZENTRAL GENOSSENSCHAFTS BANK
Rank #13
1.61%
- Shares
- 3.62M
- Change
- -1.80M
- Change %
- -33.16%
- Filing
- Mar 31, 2026
Decreased
GOLDMAN SACHS GROUP INC
Rank #14
1.59%
- Shares
- 3.57M
- Change
- +818.12K
- Change %
- +29.69%
- Filing
- Mar 31, 2026
Increased
FRANKLIN RESOURCES INC
Rank #15
1.56%
- Shares
- 3.52M
- Change
- -507.93K
- Change %
- -12.62%
- Filing
- Mar 31, 2026
Decreased
BANK OF AMERICA CORP
Rank #16
1.50%
- Shares
- 3.38M
- Change
- -900.16K
- Change %
- -21.03%
- Filing
- Mar 31, 2026
Decreased
INVESCO LTD.
Rank #17
1.15%
- Shares
- 2.60M
- Change
- +40.92K
- Change %
- +1.60%
- Filing
- Mar 31, 2026
Increased
MASSACHUSETTS FINANCIAL SERVICES CO
Rank #18
1.13%
- Shares
- 2.54M
- Change
- +527.61K
- Change %
- +26.27%
- Filing
- Mar 31, 2026
Increased
NORTHERN TRUST CORP
Rank #19
0.84%
- Shares
- 1.90M
- Change
- -3.64K
- Change %
- -19.00%
- Filing
- Mar 31, 2026
Decreased
NORGES BANK
Rank #20
0.80%
- Shares
- 1.81M
- Change
- +444.55K
- Change %
- +32.56%
- Filing
- Dec 31, 2025
Increased
| # | Institution | % held | Shares | Change | Change % | Filing date |
|---|---|---|---|---|---|---|
| 1 | 12.5% | 28.12M | -20.86K Decreased | -7.00% | Dec 31, 2025 | |
| 2 | 6.34% | 14.27M | -1.84M Decreased | -11.43% | Mar 31, 2026 | |
| 3 | 6.28% | 14.16M | +14.16M Initiated | — | Mar 31, 2026 | |
| 4 | SANDERS CAPITAL | 5.72% | 12.90M | -4.28M Decreased | -24.93% | Mar 31, 2026 |
| 5 | 4.92% | 11.09M | +11.09M Initiated | — | Mar 31, 2026 | |
| 6 | 4.14% | 9.32M | -49.17K Decreased | -53.00% | Mar 31, 2026 | |
| 7 | 3.63% | 8.18M | +4.42M Increased | +1.17% | Mar 31, 2026 | |
| 8 | 2.96% | 6.66M | -338.74K Decreased | -4.84% | Mar 31, 2026 | |
| 9 | 2.55% | 5.74M | +1.22M Increased | +27.13% | Mar 31, 2026 | |
| 10 | 2.25% | 5.06M | +164.01K Increased | +3.35% | Mar 31, 2026 | |
| 11 | 2.11% | 4.76M | -558.20K Decreased | -10.50% | Mar 31, 2026 | |
| 12 | WCM INVESTMENT MANAGEMENT | 1.93% | 4.35M | -808.02K Decreased | -15.68% | Mar 31, 2026 |
| 13 | DZ BANK AG DEUTSCHE ZENTRAL GENOSSENSCHAFTS BANK | 1.61% | 3.62M | -1.80M Decreased | -33.16% | Mar 31, 2026 |
| 14 | 1.59% | 3.57M | +818.12K Increased | +29.69% | Mar 31, 2026 | |
| 15 | 1.56% | 3.52M | -507.93K Decreased | -12.62% | Mar 31, 2026 | |
| 16 | 1.50% | 3.38M | -900.16K Decreased | -21.03% | Mar 31, 2026 | |
| 17 | 1.15% | 2.60M | +40.92K Increased | +1.60% | Mar 31, 2026 | |
| 18 | MASSACHUSETTS FINANCIAL SERVICES CO | 1.13% | 2.54M | +527.61K Increased | +26.27% | Mar 31, 2026 |
| 19 | 0.84% | 1.90M | -3.64K Decreased | -19.00% | Mar 31, 2026 | |
| 20 | 0.80% | 1.81M | +444.55K Increased | +32.56% | Dec 31, 2025 |
Showing 20 of 120 matching institutional rows.Load more institutions
Recent insider transactions
Seagate Technology PLC (STX) Form 4 filings
Action codes are translated so open-market buys and sales are separate from awards, gifts, conversions, and tax withholding.
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 120
- % company
- <0.01%
- Price
- $763.18
- Value
- $91,582
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 14.00K
- % company
- <0.01%
- Price
- Not reported
- Value
- Not reported
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 14.00K
- % company
- <0.01%
- Price
- $46.23
- Value
- $647,220
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 120
- % company
- <0.01%
- Price
- $742.01
- Value
- $89,041
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 560
- % company
- <0.01%
- Price
- $743.14
- Value
- $416,158
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 840
- % company
- <0.01%
- Price
- $744.52
- Value
- $625,394
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 1.26K
- % company
- <0.01%
- Price
- $745.55
- Value
- $942,379
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 1.46K
- % company
- <0.01%
- Price
- $746.53
- Value
- $1,092,177
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 1.60K
- % company
- <0.01%
- Price
- $747.64
- Value
- $1,199,956
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 1.72K
- % company
- <0.01%
- Price
- $748.53
- Value
- $1,286,722
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 1.62K
- % company
- <0.01%
- Price
- $749.67
- Value
- $1,213,715
Filed May 20, 2026
MOSLEY, WILLIAM D
Director, CEO
- Shares
- 4.81K
- % company
- <0.01%
- Price
- $750.84
- Value
- $3,611,564
Filed May 20, 2026
| # | Insider | % company | Action | Shares | Price | Value | Filing date |
|---|---|---|---|---|---|---|---|
| 1 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 120 | $763.18 | $91,582 | May 20, 2026 |
| 2 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 14.00K | Not reported | Not reported | May 20, 2026 |
| 3 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Award / grant | 14.00K | $46.23 | $647,220 | May 20, 2026 |
| 4 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 120 | $742.01 | $89,041 | May 20, 2026 |
| 5 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 560 | $743.14 | $416,158 | May 20, 2026 |
| 6 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 840 | $744.52 | $625,394 | May 20, 2026 |
| 7 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 1.26K | $745.55 | $942,379 | May 20, 2026 |
| 8 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 1.46K | $746.53 | $1,092,177 | May 20, 2026 |
| 9 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 1.60K | $747.64 | $1,199,956 | May 20, 2026 |
| 10 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 1.72K | $748.53 | $1,286,722 | May 20, 2026 |
| 11 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 1.62K | $749.67 | $1,213,715 | May 20, 2026 |
| 12 | MOSLEY, WILLIAM D Director, CEO | <0.01% | Sale to issuer | 4.81K | $750.84 | $3,611,564 | May 20, 2026 |
Showing 12 of 120 matching Form 4 rows. Percent of company uses current shares outstanding when available.Load more insiders
Frequently asked
Common questions.
Who are the largest STX shareholders?
VANGUARD GROUP INC is the largest institutional holder in the loaded STX ownership feed, with 28.12 million shares, or about 12.48% of shares outstanding. The table ranks additional institutions by reported share count.
What is institutional ownership of STX?
The current TECHi snapshot has 120 loaded institutional rows for Seagate Technology PLC. 61 rows are marked increased or initiated, while 57 rows are marked decreased, with the latest holder filing dated Mar 31, 2026.
Where can I see Seagate Technology PLC insider transactions?
The insider transaction table currently shows 120 loaded Form 4 rows for STX, with the latest insider filing dated May 20, 2026. It separates purchases, sales, option exercises, awards, gifts, and tax withholding so administrative transactions are not confused with open-market trades.
Are STX insiders buying or selling?
The loaded STX Form 4 rows currently read Net selling: 115 sale rows and 0 purchase rows. Awards, gifts, conversions, and tax withholding are shown separately because they do not carry the same signal as open-market buying or selling.
Who is the most active STX insider in the loaded filings?
MOSLEY, WILLIAM D is the most active insider by absolute share movement in the loaded STX rows, with 76,100 shares moving across the visible filing history. Review the action labels before treating that activity as buying or selling.