STX
Seagate Technology PLC
545.10$
-1.2%
vs. previous close
Closing price · As of: Nov 12, 2026
Ownership
Ownership Structure
Who owns Seagate Technology PLC (STX)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 99.7% of the shares are freely tradable; institutional investors hold 84.7%.
Institutional ownership
?Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings.
84.7%
Insiders
?Share of the stock held by the executives, founders and major shareholders of the company itself.
0.2%
Float
?Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders.
99.7%
Short % of float
?Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices.
3.4%
Shares Outstanding
?Total number of shares issued. Price times share count gives market cap.
230Mio.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 6.61 | 15,166,793 | +6.3 | 06/30/2026 |
| Vanguard Capital Management, LLC | 6.37 | 14,630,067 | +3.4 | 06/30/2026 |
| State Street Corp | 4.32 | 9,911,669 | +6.3 | 06/30/2026 |
| FMR Inc | 3.55 | 8,153,134 | -0.3 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 3.48 | 7,999,686 | -27.9 | 06/30/2026 |
| Amvescap Plc. | 3.28 | 7,536,880 | +5.0 | 06/30/2026 |
| WCM Investment Management | 2.32 | 5,320,463 | +22.4 | 06/30/2026 |
| JPMorgan Chase & Co | 2.27 | 5,201,103 | -21.9 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 3.13 | 7,193,807 | +1.0 | 09/30/2026 |
| Vanguard 500 Index Investor | 2.59 | 5,953,671 | -0.1 | 09/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Mosley William D | CEO | 346,348 | 188,794,431 $ | Nov 2, 2026 | direct |
| Romano Gianluca | EVP & CFO | 70,757 | 38,569,368 $ | Sep 15, 2026 | direct |
| Clemmer Richard L | Director | 30,904 | 16,845,770 $ | Oct 24, 2026 | direct |
| Chong Kian Fatt | EVP Global Operations | 25,093 | 13,678,194 $ | Sep 14, 2026 | direct |
| Morris John Christopher | EVP & CTO | 20,933 | 11,410,715 $ | Oct 30, 2026 | direct |
| Haggart Dylan G. | Director | 15,715 | 8,566,247 $ | Oct 24, 2026 | direct |
| Cannon Michael R | Director | 14,858 | 8,099,096 $ | Oct 24, 2026 | direct |
| Bhatt Prat | Director | 14,069 | 7,669,012 $ | Oct 24, 2026 | direct |
| Tilenius Stephanie | Director | 11,864 | 6,467,066 $ | Oct 24, 2026 | direct |
| Arumugavelu Shankar | Director | 7,826 | 4,265,953 $ | Oct 24, 2026 | direct |
| Teh Ban Seng | EVP & Chief Commercial Officer | 5,810 | 3,167,031 $ | Sep 15, 2026 | direct |
| Conyers Yolanda Lee | Director | 4,551 | 2,480,750 $ | Oct 24, 2026 | direct |
| Adams Mark | Director | 3,246 | 1,769,395 $ | Oct 24, 2026 | direct |
| Szlosek Thomas A | Director | 1,558 | 849,478 $ | Oct 24, 2026 | direct |
| Geldmacher Jay L | Director | 1,423 | 775,677 $ | Oct 24, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Nov 2, 2026 | Mosley William D | CEO | Sell | 120 | 640.46 | 76,855 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 160 | 642.78 | 102,845 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 80 | 644.43 | 51,554 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 320 | 625.68 | 200,217 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 640 | 623.91 | 399,302 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,080 | 621.89 | 671,646 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,160 | 619.60 | 718,732 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 960 | 617.67 | 592,961 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 760 | 618.80 | 470,286 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 920 | 613.44 | 564,364 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 520 | 612.35 | 318,422 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 680 | 610.17 | 414,918 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,177 | 609.41 | 717,274 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 891 | 608.40 | 542,083 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 2,372 | 607.28 | 1,440,465 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,082 | 606.25 | 655,958 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,600 | 605.30 | 968,477 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 400 | 601.26 | 240,502 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,200 | 600.07 | 720,087 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 560 | 611.30 | 342,328 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 481 | 597.91 | 287,593 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 240 | 633.64 | 152,073 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 678 | 595.68 | 403,870 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,480 | 594.55 | 879,929 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,639 | 593.47 | 972,692 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 1,400 | 592.71 | 829,794 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 280 | 614.54 | 172,070 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 800 | 615.31 | 492,247 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 600 | 603.67 | 362,199 |
| Nov 2, 2026 | Mosley William D | CEO | Sell | 720 | 620.80 | 446,978 |
| Nov 2, 2026 | Mosley William D | CEO | Other | 14,000 | 46.23 | 647,220 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 6 | 678.44 | 4,071 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 34 | 677.05 | 23,020 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 120 | 670.18 | 80,422 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 132 | 660.64 | 87,204 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 68 | 659.56 | 44,850 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 995 | 653.78 | 650,511 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 160 | 656.99 | 105,118 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 118 | 631.69 | 74,540 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 82 | 630.19 | 51,675 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 40 | 663.14 | 26,526 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Sell | 80 | 665.06 | 53,204 |
| Oct 30, 2026 | Morris John Christopher | EVP & CTO | Other | 915 | 158.40 | 144,936 |
| Oct 24, 2026 | Tilenius Stephanie | Director | Other | 380 | 630.49 | 239,586 |
| Oct 24, 2026 | Tilenius Stephanie | Director | Other | 1,580 | 0.00 | – |
| Oct 24, 2026 | Szlosek Thomas A | Director | Other | 380 | 630.49 | 239,586 |
| Oct 24, 2026 | Szlosek Thomas A | Director | Other | 1,580 | 0.00 | – |
| Oct 24, 2026 | Haggart Dylan G. | Director | Other | 380 | 630.49 | 239,586 |
| Oct 24, 2026 | Haggart Dylan G. | Director | Other | 1,580 | 0.00 | – |
| Oct 24, 2026 | Geldmacher Jay L | Director | Other | 380 | 630.49 | 239,586 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: November 12, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.