Seagate Technology Holdings plc
Seagate Technology Holdings plc (STX) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · STX · as of Sep 30, 2025
Ownership Breakdown
1,201
Institutional Holders
▲ 188 vs Q2
$45.54B
Total Inst. Value
▲ $16.90B vs Q2
224.23M
Shares Outstanding
freeFloat 99.67%
193.08M
13F Shares Held
▼ 5.32M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
STX largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC computer storage devices | 28.14M | 13.27% | 13.27% | $6.64T | Nov 7, 2025 | ▲ 442.7K |
SANDERS CAPITAL, LLC computer storage devices | 17.54M | 8.27% | 8.27% | $4.14T | Nov 13, 2025 | ▼ 541.0K |
BLACKROCK, INC. computer storage devices | 14.40M | 6.79% | 6.79% | $3.40T | Nov 12, 2025 | ▲ 496.6K |
JPMORGAN CHASE & CO computer storage devices | 13.93M | 6.57% | 6.57% | $3.29T | Nov 26, 2025 | ▼ 4.76M |
STATE STREET CORP computer storage devices | 9.28M | 4.38% | 4.38% | $2.20T | Nov 14, 2025 | ▲ 274.9K |
FRANKLIN RESOURCES INC computer storage devices | 8.07M | 3.81% | 3.81% | $1.90T | Nov 13, 2025 | ▼ 219.2K |
BANK OF AMERICA CORP /DE/ computer storage devices | 7.59M | 3.58% | 3.58% | $1.79T | Feb 3, 2026 | ▲ 985.3K |
CAPITAL RESEARCH GLOBAL INVESTORS computer storage devices | 6.19M | 2.92% | 2.92% | $1.46T | Nov 13, 2025 | ▼ 1.10M |
WCM INVESTMENT MANAGEMENT, LLC computer storage devices | 5.18M | 2.44% | 2.44% | $1.19T | Nov 4, 2025 | NEW |
MORGAN STANLEY computer storage devices | 5.06M | 2.39% | 2.39% | $1.19T | May 27, 2026 | ▼ 429.1K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
29
Increased
+14.37M shares3
New Positions
first time holders18
Decreased
−16.15M shares0
Sold Out
fully exitedNet shares change (top 50)
1.78M
+14.37M / −16.15M
Net new holders
+14
3 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
STX insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
6
Buy transactions
170
Sell transactions
0.04
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Arumugavelu Shankar director | Jun 4, 2026 | Sale | 1,000 | $927.68 | $927.7K | 6.6K | Form 4 ↗ |
BHATT PRAT director | Jun 2, 2026 | Sale | 1,000 | $929.88 | $929.9K | 12.9K | Form 4 ↗ |
Conyers Yolanda Lee director | Jun 1, 2026 | Sale | 750 | $885.33 | $664.0K | 4.1K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 320 | $916.77 | $293.4K | 337.1K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 480 | $918.75 | $441.0K | 336.6K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 1,691 | $919.62 | $1.56M | 334.9K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 1,730 | $920.90 | $1.59M | 333.1K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 1,807 | $921.75 | $1.67M | 331.3K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 1,598 | $922.95 | $1.47M | 329.7K | Form 4 ↗ |
MOSLEY WILLIAM D CEO | Jun 1, 2026 | Sale | 480 | $923.58 | $443.3K | 329.3K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Seagate Technology Holdings plc (STX) is primarily owned by institutional investors, who hold approximately 86.1% of total shares outstanding. Company insiders own approximately 0.33%, while retail and public investors account for the remaining 13.56%.
The largest institutional shareholder of Seagate Technology Holdings plc is VANGUARD GROUP INC, holding approximately 28.14 million shares — equal to 13.27% of outstanding shares — as of September 30, 2025.
A total of 1,201 institutional investors currently hold STX stock, with a combined institutional value of approximately $45.54 billion as of the most recent 13F filing period.
Frequently asked questions
STX ownershipSeagate Technology Holdings plc (STX) is primarily owned by institutional investors, who hold approximately 86.1% of shares. The largest shareholder is VANGUARD GROUP INC with a 13.27% stake. Company insiders hold 0.33%. Data sourced from SEC Form 13F as of September 30, 2025.