Seagate Technology Holdings (STX) insider trading
Recent insider transactions reported to the SEC on Form 4 — directors and officers buying or selling their own company’s stock. Sourced directly from public SEC filings, latest filed Oct 2, 2026.
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- Filings shown
- 38
- Open-market buys
- 0
- Open-market sells
- 379
Counts cover the 38 most recent Form 4 filings Tradune holds for STX (filed Jul 24 – Oct 2, 2026). No completed check of STX's Form 4 list on SEC EDGAR is on record yet; the latest STX filing Tradune holds was filed Oct 2, 2026. This is not guaranteed to be the complete record — see STX's full Form 4 filing history on SEC EDGAR.
Open-market activity, last 90 days
Purchases (Form 4 code P) and sales (code S) on the 38 filings Tradune holds for STX filed Jul 24 – Oct 2, 2026. Grants, exercises, tax withholding and the other Form 4 transaction codes are left out.
379 open-market sales by Rule 10b5-1 checkbox
- On filings with the 10b5-1 box checked
- 162 sales· 175,939 sh
- checkbox disclosed
- On filings with the box not checked
- 11 sales· 170,470 sh
- not proof that no plan exists
- Not comparable
- 206 sales· 121,091 sh
- filed before Apr 1, 2023, or no checkbox value in the filing data
Counts are Form 4 lines as filed. The checkbox is one per filing, so every sale on a filing with the box checked is counted there even if only some of its transactions were under a plan; it records what the filer disclosed, and the three categories are not a judgement about why a sale was made.
| Insider | Buys | Sells | Shares bought | Shares sold | Value |
|---|---|---|---|---|---|
| William D. MosleyCEO | 0 | 125 | — | 210,747 | −$171,577,539 |
| Gianluca RomanoEVP & CFO | 0 | 110 | — | 134,072 | −$108,073,270 |
| Ban Seng TehEVP & Chief Commercial Officer | 0 | 74 | — | 77,653 | −$62,868,053 |
| John Christopher MorrisEVP & CTO | 0 | 35 | — | 30,091 | −$24,592,240 |
| James Ci LeeEVP & CLO | 0 | 34 | — | 14,188 | −$11,609,013 |
| Yolanda Lee ConyersDirector | 0 | 1 | — | 750 | −$611,333 |
Value = shares × the price reported on each Form 4 (+ purchases, − sales); every open-market line in this window disclosed a price.
Insider-activity score
0/ 100
0 distinct buyers0 buy · 379 sell tx
Summarises ~90 days of public SEC Form 4 activity — more distinct buyers, officer involvement and net buying score higher. A description of filing activity, not a rating or buy signal. How this score is computed →
How to read this: an open-market purchase (Form 4 code P) is a buy at the market price with the insider’s own money, as opposed to a grant, award or option exercise; an open-market sale is code S. When two or more distinct insiders report open-market purchases in the same 90-day window, this site labels that a cluster — a definition, not a forecast; see insider cluster buying. “Held after” is Form 4 Table I column 5; “Change” = shares ÷ holdings before the trade (held after − shares for an acquisition, held after + shares for a disposition).
Insider Buying at STX
No open-market insider purchases (Form 4 code P) were reported for STX in the trailing 90 days. The filings below may include other transaction types — sales, grants, option exercises, and tax withholding — shown for completeness; they are not open-market purchases.
Recent Form 4 filings
Source: SEC EDGAR Form 4 · transaction codes explained
William D. Mosley CEO · filed Oct 2, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 360 | $929.01 | 372,750 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 855 | $930.03 | 371,895 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,665 | $930.99 | 370,230 | −0.4% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,320 | $932.04 | 368,910 | −0.4% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 840 | $933.28 | 368,070 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 822 | $934.35 | 367,248 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 640 | $935.15 | 366,608 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 759 | $936.43 | 365,849 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 579 | $937.33 | 365,270 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 640 | $938.32 | 364,630 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 720 | $939.27 | 363,910 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $940.20 | 363,830 | −0.0% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $941.22 | 363,790 | −0.0% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 280 | $943.21 | 363,510 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 440 | $944.81 | 363,070 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 962 | $945.97 | 362,108 | −0.3% | Oct 1, 2026 |
† change in this filer’s own reported holding line (Form 4 Table I, col. 5), not of total company ownership; small prior holdings produce large percentages, so under 100 shares the prior holding is shown instead.
“10b5-1 box checked” = the filer checked the Form 4 box stating that a transaction on the filing was made under a plan intended to satisfy Rule 10b5-1(c); “10b5-1 box not checked” = the box was left blank, which does not prove that no plan exists. The box applies to Form 4s filed from April 1, 2023; older filings, and boxes we could not read, carry no tag. What the 10b5-1 box means.
William D. Mosley CEO · filed Oct 2, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 1,027 | $908.58 | 386,563 | −0.3% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 400 | $917.22 | 380,830 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 920 | $918.49 | 379,910 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 840 | $919.56 | 379,070 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 630 | $920.62 | 378,440 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 930 | $921.64 | 377,510 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 800 | $922.66 | 376,710 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 760 | $923.78 | 375,950 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 640 | $924.72 | 375,310 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,080 | $925.88 | 374,230 | −0.3% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 480 | $926.78 | 373,750 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 640 | $927.90 | 373,110 | −0.2% | Oct 1, 2026 |
| Option exercise NQ Options | 14,000 | — | — | — | Oct 1, 2026 |
| Option exercise | 14,000 | $46.23 | 392,108 | +3.7% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 360 | $898.10 | 391,748 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 517 | $900.46 | 391,231 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 440 | $901.49 | 390,791 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 384 | $902.55 | 390,407 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 696 | $903.36 | 389,711 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 480 | $904.33 | 389,231 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 480 | $905.38 | 388,751 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 601 | $906.42 | 388,150 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 560 | $907.43 | 387,590 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 480 | $916.10 | 381,230 | −0.1% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 960 | $915.01 | 381,710 | −0.3% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 904 | $913.94 | 382,670 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 696 | $913.08 | 383,574 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,146 | $912.04 | 384,270 | −0.3% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 840 | $910.69 | 385,416 | −0.2% | Oct 1, 2026 |
| Open-market sale 10b5-1 box checked | 307 | $909.84 | 386,256 | −0.1% | Oct 1, 2026 |
John Christopher Morris EVP & CTO · filed Sep 22, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 40 | $902.07 | 22,693 | −0.2% | Sep 21, 2026 |
| Option exercise | 915 | $158.40 | 32,047 | +2.9% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $863.66 | 32,007 | −0.1% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $865.11 | 31,927 | −0.2% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $865.80 | 31,887 | −0.1% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 160 | $868.11 | 31,727 | −0.5% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $869.21 | 31,647 | −0.3% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 200 | $870.28 | 31,447 | −0.6% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 520 | $871.56 | 30,927 | −1.7% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 1,000 | $872.42 | 29,927 | −3.2% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 1,040 | $873.49 | 28,887 | −3.5% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 986 | $874.50 | 27,901 | −3.4% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 974 | $875.35 | 26,927 | −3.5% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 760 | $876.54 | 26,167 | −2.8% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 418 | $877.36 | 25,749 | −1.6% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 280 | $878.38 | 25,469 | −1.1% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 200 | $879.71 | 25,269 | −0.8% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 741 | $881.16 | 24,528 | −2.9% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 200 | $881.90 | 24,328 | −0.8% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 320 | $883.08 | 24,008 | −1.3% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $886.27 | 23,968 | −0.2% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 120 | $887.92 | 23,848 | −0.5% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $890.54 | 23,808 | −0.2% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $893.15 | 23,768 | −0.2% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 915 | $894.27 | 22,853 | −3.8% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $897.28 | 22,773 | −0.4% | Sep 21, 2026 |
| Open-market sale 10b5-1 box checked | 40 | $899.53 | 22,733 | −0.2% | Sep 21, 2026 |
| Option exercise NQ Stock Option | 915 | — | — | — | Sep 21, 2026 |
Gianluca Romano EVP & CFO · filed Sep 16, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 49,984 | $772.16 | 70,757 | −41% | Sep 15, 2026 |
| Option exercise Performance-Based Restricted Share Units | 90,380 | — | — | — | Sep 14, 2026 |
| Option exercise | 90,380 | — | 120,740 | +298% | Sep 14, 2026 |
William D. Mosley CEO · filed Sep 16, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 97,889 | $772.14 | 378,108 | −21% | Sep 15, 2026 |
| Option exercise Performance-Based Restricted Share Units | 177,000 | — | — | — | Sep 14, 2026 |
| Option exercise | 177,000 | — | 475,998 | +59% | Sep 14, 2026 |
Ban Seng Teh EVP & Chief Commercial Officer · filed Sep 16, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 2,480 | $800.47 | 5,810 | −30% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 400 | $799.03 | 8,290 | −4.6% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 530 | $797.97 | 8,690 | −5.7% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,587 | $796.90 | 9,220 | −15% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 2,166 | $795.95 | 10,807 | −17% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,280 | $794.72 | 12,973 | −9.0% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 560 | $791.36 | 14,253 | −3.8% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,760 | $789.84 | 14,813 | −11% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 280 | $788.43 | 16,573 | −1.7% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 120 | $787.26 | 16,853 | −0.7% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,040 | $786.14 | 16,973 | −5.8% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,000 | $784.45 | 18,013 | −5.3% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,760 | $783.28 | 19,013 | −8.5% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 4,147 | $782.56 | 20,773 | −17% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,600 | $781.35 | 24,920 | −6.0% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 2,453 | $780.29 | 26,520 | −8.5% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 6,682 | $779.27 | 28,973 | −19% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 7,259 | $778.35 | 35,655 | −17% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 3,987 | $777.22 | 42,914 | −8.5% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 3,242 | $776.20 | 46,901 | −6.5% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 2,315 | $775.01 | 50,143 | −4.4% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,717 | $774.01 | 52,458 | −3.2% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 3,451 | $772.65 | 54,175 | −6.0% | Sep 15, 2026 |
| Open-market sale 10b5-1 box checked | 914 | $771.38 | 57,626 | −1.6% | Sep 15, 2026 |
| Option exercise Performance-Based Restricted Share Units | 52,730 | — | — | — | Sep 14, 2026 |
| Option exercise | 52,730 | — | 58,540 | +908% | Sep 14, 2026 |
John Christopher Morris EVP & CTO · filed Sep 16, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 15,466 | $772.15 | 31,132 | −33% | Sep 15, 2026 |
| Option exercise Performance-Based Restricted Share Units | 30,130 | — | — | — | Sep 14, 2026 |
| Option exercise | 30,130 | — | 46,598 | +183% | Sep 14, 2026 |
Kian Fatt Chong EVP Global Operations · filed Sep 16, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise | 14,470 | — | 25,093 | +136% | Sep 14, 2026 |
| Option exercise Performance-Based Restricted Share Units | 14,470 | — | — | — | Sep 14, 2026 |
Ban Seng Teh EVP & Chief Commercial Officer · filed Sep 15, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 989 | $779.00 | 5,810 | −15% | Sep 14, 2026 |
| Option exercise | 989 | — | 6,799 | +17% | Sep 11, 2026 |
| Option exercise Restricted Share Unit | 989 | — | — | — | Sep 11, 2026 |
John Christopher Morris EVP & CTO · filed Sep 15, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 493 | $781.23 | 16,468 | −2.9% | Sep 14, 2026 |
| Option exercise | 942 | — | 16,961 | +5.9% | Sep 11, 2026 |
| Option exercise Restricted Share Unit | 942 | — | — | — | Sep 11, 2026 |
Gianluca Romano EVP & CFO · filed Sep 15, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 955 | $781.24 | 30,360 | −3.0% | Sep 14, 2026 |
| Open-market sale 10b5-1 box checked | 280 | $860.47 | 30,460 | −0.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 280 | $861.07 | 30,180 | −0.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 320 | $864.41 | 29,860 | −1.1% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 240 | $868.43 | 29,620 | −0.8% | Sep 11, 2026 |
| Option exercise | 1,695 | — | 31,315 | +5.7% | Sep 11, 2026 |
| Option exercise Restricted Share Unit | 1,695 | — | — | — | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 240 | $855.72 | 30,980 | −0.8% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 240 | $857.41 | 30,740 | −0.8% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 680 | $854.41 | 31,220 | −2.1% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 320 | $851.45 | 32,540 | −1.0% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $849.87 | 32,860 | −0.2% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 560 | $849.53 | 32,940 | −1.7% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 320 | $847.98 | 33,500 | −0.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 200 | $846.94 | 33,820 | −0.6% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 200 | $844.81 | 34,020 | −0.6% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 640 | $852.87 | 31,900 | −2.0% | Sep 11, 2026 |
William D. Mosley CEO · filed Sep 15, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 1,870 | $781.23 | 298,998 | −0.6% | Sep 14, 2026 |
| Option exercise | 3,319 | — | 300,867 | +1.1% | Sep 11, 2026 |
| Option exercise Restricted Share Unit | 3,319 | — | — | — | Sep 11, 2026 |
Kian Fatt Chong EVP Global Operations · filed Sep 15, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise | 678 | — | 10,623 | +6.8% | Sep 11, 2026 |
| Option exercise Restricted Share Unit | 678 | — | — | — | Sep 11, 2026 |
Gianluca Romano EVP & CFO · filed Sep 15, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 1,400 | $824.60 | 72,238 | −1.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 880 | $823.72 | 73,638 | −1.2% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,690 | $822.50 | 74,518 | −2.2% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,550 | $821.42 | 76,208 | −2.0% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,320 | $820.54 | 77,758 | −1.7% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,040 | $819.39 | 79,078 | −1.3% | Sep 11, 2026 |
| Option exercise | 8,517 | $68.83 | 38,137 | +29% | Sep 11, 2026 |
| Option exercise | 15,067 | $64.31 | 53,204 | +40% | Sep 11, 2026 |
| Option exercise | 13,475 | $101.34 | 66,679 | +25% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 5,593 | $829.77 | 58,957 | −8.7% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,727 | $827.72 | 67,871 | −2.5% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,840 | $826.72 | 69,598 | −2.6% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 800 | $825.65 | 71,438 | −1.1% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 2,080 | $833.67 | 40,500 | −4.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 4,220 | $832.68 | 42,580 | −9.0% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 4,589 | $831.71 | 46,800 | −8.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 7,568 | $830.74 | 51,389 | −13% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 3,321 | $828.84 | 64,550 | −4.9% | Sep 11, 2026 |
| Option exercise NQ Options | 15,067 | — | — | — | Sep 11, 2026 |
| Option exercise NQ Options | 13,475 | — | — | — | Sep 11, 2026 |
| Option exercise NQ Stock Option | 13,439 | — | — | — | Sep 11, 2026 |
| Option exercise | 13,439 | $158.40 | 80,118 | +20% | Sep 11, 2026 |
| Option exercise NQ Options | 8,517 | — | — | — | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 360 | $843.55 | 34,220 | −1.0% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 280 | $842.23 | 34,580 | −0.8% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 320 | $841.05 | 34,860 | −0.9% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,000 | $840.12 | 35,180 | −2.8% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 880 | $839.15 | 36,180 | −2.4% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 200 | $838.10 | 37,060 | −0.5% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 480 | $836.92 | 37,260 | −1.3% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,320 | $835.67 | 37,740 | −3.4% | Sep 11, 2026 |
| Open-market sale 10b5-1 box checked | 1,440 | $834.80 | 39,060 | −3.6% | Sep 11, 2026 |
Ban Seng Teh EVP & Chief Commercial Officer · filed Sep 11, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 663 | $860.09 | 5,810 | −10% | Sep 10, 2026 |
| Option exercise | 600 | — | 5,810 | +12% | Sep 9, 2026 |
| Option exercise | 663 | — | 6,473 | +11% | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 600 | — | — | — | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 663 | — | — | — | Sep 9, 2026 |
John Christopher Morris EVP & CTO · filed Sep 11, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 319 | $862.14 | 16,019 | −2.0% | Sep 10, 2026 |
| Open-market sale 10b5-1 box not checked | 253 | $862.13 | 15,707 | −1.6% | Sep 10, 2026 |
| Option exercise Restricted Share Unit | 500 | — | — | — | Sep 9, 2026 |
| Option exercise | 500 | — | 15,960 | +3.2% | Sep 9, 2026 |
| Option exercise | 631 | — | 16,338 | +4.0% | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 631 | — | — | — | Sep 9, 2026 |
Gianluca Romano EVP & CFO · filed Sep 11, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 826 | $862.13 | 29,620 | −2.7% | Sep 10, 2026 |
| Open-market sale 10b5-1 box not checked | 523 | $862.13 | 28,931 | −1.8% | Sep 10, 2026 |
| Option exercise | 959 | — | 29,453 | +3.4% | Sep 9, 2026 |
| Option exercise | 1,515 | — | 30,446 | +5.2% | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 959 | — | — | — | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 1,515 | — | — | — | Sep 9, 2026 |
William D. Mosley CEO · filed Sep 11, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 1,534 | $862.13 | 296,449 | −0.5% | Sep 10, 2026 |
| Open-market sale 10b5-1 box not checked | 1,316 | $862.14 | 297,548 | −0.4% | Sep 10, 2026 |
| Option exercise | 2,815 | — | 297,983 | +1.0% | Sep 9, 2026 |
| Option exercise | 2,415 | — | 298,864 | +0.8% | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 2,815 | — | — | — | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 2,415 | — | — | — | Sep 9, 2026 |
Kian Fatt Chong EVP Global Operations · filed Sep 11, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise | 379 | — | 9,945 | +4.0% | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 202 | — | — | — | Sep 9, 2026 |
| Option exercise Restricted Share Unit | 379 | — | — | — | Sep 9, 2026 |
| Option exercise | 202 | — | 9,566 | +2.2% | Sep 9, 2026 |
William D. Mosley CEO · filed Sep 3, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 2,040 | $813.74 | 316,448 | −0.6% | Sep 1, 2026 |
| Option exercise | 14,000 | $46.23 | 325,168 | +4.5% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $829.10 | 295,328 | −0.0% | Sep 1, 2026 |
| Option exercise NQ Options | 14,000 | — | — | — | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,200 | $812.55 | 318,488 | −0.4% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 120 | $827.90 | 295,408 | −0.0% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,578 | $811.73 | 319,688 | −0.5% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 340 | $826.86 | 295,528 | −0.1% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,105 | $810.78 | 321,266 | −0.3% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,160 | $809.55 | 322,371 | −0.4% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 960 | $808.62 | 323,531 | −0.3% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 580 | $826.00 | 295,868 | −0.2% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $832.05 | 295,168 | −0.0% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 160 | $807.19 | 324,491 | −0.0% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 80 | $830.36 | 295,248 | −0.0% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 600 | $824.93 | 296,448 | −0.2% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 160 | $805.55 | 324,651 | −0.0% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 357 | $804.61 | 324,811 | −0.1% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,240 | $824.05 | 297,048 | −0.4% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 600 | $822.89 | 298,288 | −0.2% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 480 | $822.05 | 298,888 | −0.2% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 920 | $820.89 | 299,368 | −0.3% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,320 | $819.84 | 300,288 | −0.4% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 1,040 | $818.78 | 301,608 | −0.3% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 2,080 | $817.71 | 302,648 | −0.7% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 4,287 | $816.75 | 304,728 | −1.4% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 4,555 | $815.75 | 309,015 | −1.5% | Sep 1, 2026 |
| Open-market sale 10b5-1 box checked | 2,878 | $814.75 | 313,570 | −0.9% | Sep 1, 2026 |
Yolanda Lee Conyers Director · filed Sep 3, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 750 | $815.11 | 3,351 | −18% | Sep 1, 2026 |
James Ci Lee EVP & CLO · filed Aug 26, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 600 | $797.39 | — | — | Aug 24, 2026 |
| Open-market sale | 200 | $801.60 | — | — | Aug 24, 2026 |
| Open-market sale | 968 | $794.77 | — | — | Aug 24, 2026 |
| Open-market sale | 440 | $803.57 | — | — | Aug 24, 2026 |
| Open-market sale | 120 | $809.61 | — | — | Aug 24, 2026 |
| Open-market sale | 40 | $816.96 | — | — | Aug 24, 2026 |
| Option exercise | 4,032 | $158.40 | — | — | Aug 24, 2026 |
| Open-market sale | 40 | $774.84 | — | — | Aug 24, 2026 |
| Open-market sale | 112 | $776.14 | — | — | Aug 24, 2026 |
| Open-market sale | 8 | $777.05 | — | — | Aug 24, 2026 |
| Open-market sale | 80 | $778.51 | — | — | Aug 24, 2026 |
| Open-market sale | 160 | $780.66 | — | — | Aug 24, 2026 |
| Open-market sale | 280 | $782.33 | — | — | Aug 24, 2026 |
| Open-market sale | 280 | $783.28 | — | — | Aug 24, 2026 |
| Open-market sale | 120 | $784.66 | — | — | Aug 24, 2026 |
| Open-market sale | 240 | $786.27 | — | — | Aug 24, 2026 |
| Open-market sale | 200 | $788.03 | — | — | Aug 24, 2026 |
| Open-market sale | 560 | $789.25 | — | — | Aug 24, 2026 |
| Open-market sale | 280 | $790.34 | — | — | Aug 24, 2026 |
| Open-market sale | 440 | $791.80 | — | — | Aug 24, 2026 |
| Open-market sale | 120 | $792.39 | — | — | Aug 24, 2026 |
| Open-market sale | 480 | $793.66 | — | — | Aug 24, 2026 |
| Open-market sale | 480 | $800.42 | — | — | Aug 24, 2026 |
| Open-market sale | 567 | $799.44 | — | — | Aug 24, 2026 |
| Open-market sale | 845 | $795.90 | — | — | Aug 24, 2026 |
| Open-market sale | 593 | $802.67 | — | — | Aug 24, 2026 |
| Open-market sale | 40 | $814.27 | — | — | Aug 24, 2026 |
| Open-market sale | 80 | $804.87 | — | — | Aug 24, 2026 |
| Open-market sale | 600 | $798.49 | — | — | Aug 24, 2026 |
| Open-market sale | 40 | $812.72 | — | — | Aug 24, 2026 |
Ban Seng Teh EVP & Chief Commercial Officer · filed Aug 24, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 120 | $865.77 | — | — | Aug 21, 2026 |
| Open-market sale | 80 | $835.55 | — | — | Aug 21, 2026 |
| Open-market sale | 89 | $837.27 | — | — | Aug 21, 2026 |
| Open-market sale | 88 | $838.35 | — | — | Aug 21, 2026 |
| Open-market sale | 280 | $839.60 | — | — | Aug 21, 2026 |
| Open-market sale | 200 | $840.53 | — | — | Aug 21, 2026 |
| Open-market sale | 440 | $841.60 | — | — | Aug 21, 2026 |
| Open-market sale | 240 | $842.69 | — | — | Aug 21, 2026 |
| Open-market sale | 120 | $843.64 | — | — | Aug 21, 2026 |
| Open-market sale | 228 | $845.15 | — | — | Aug 21, 2026 |
| Open-market sale | 360 | $846.39 | — | — | Aug 21, 2026 |
| Open-market sale | 920 | $847.36 | — | — | Aug 21, 2026 |
| Open-market sale | 520 | $848.47 | — | — | Aug 21, 2026 |
| Open-market sale | 267 | $849.27 | — | — | Aug 21, 2026 |
| Open-market sale | 440 | $850.63 | — | — | Aug 21, 2026 |
| Open-market sale | 560 | $851.71 | — | — | Aug 21, 2026 |
| Open-market sale | 510 | $852.90 | — | — | Aug 21, 2026 |
| Open-market sale | 160 | $854.21 | — | — | Aug 21, 2026 |
| Open-market sale | 240 | $855.18 | — | — | Aug 21, 2026 |
| Open-market sale | 720 | $857.16 | — | — | Aug 21, 2026 |
| Open-market sale | 280 | $858.23 | — | — | Aug 21, 2026 |
| Open-market sale | 80 | $859.30 | — | — | Aug 21, 2026 |
| Open-market sale | 500 | $860.50 | — | — | Aug 21, 2026 |
| Open-market sale | 221 | $861.26 | — | — | Aug 21, 2026 |
| Open-market sale | 1,759 | $861.81 | — | — | Aug 21, 2026 |
| Open-market sale | 360 | $863.21 | — | — | Aug 21, 2026 |
| Open-market sale | 80 | $868.00 | — | — | Aug 21, 2026 |
John Christopher Morris EVP & CTO · filed Aug 24, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 879 | $849.35 | — | — | Aug 21, 2026 |
| Open-market sale | 2,028 | $849.35 | — | — | Aug 21, 2026 |
| Open-market sale | 609 | $849.35 | — | — | Aug 21, 2026 |
| Open-market sale | 523 | $835.54 | — | — | Aug 20, 2026 |
| Option exercise | 523 | $158.40 | — | — | Aug 20, 2026 |
| Option exercise | 1,221 | — | — | — | Aug 20, 2026 |
| Option exercise | 4,070 | — | — | — | Aug 20, 2026 |
| Option exercise | 1,764 | — | — | — | Aug 20, 2026 |
James Ci Lee EVP & CLO · filed Aug 24, 2026 ·
SEC ↗
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale | 668 | $849.35 | — | — | Aug 21, 2026 |
| Open-market sale | 755 | $849.35 | — | — | Aug 21, 2026 |
| Open-market sale | 2,516 | $849.35 | — | — | Aug 21, 2026 |
| Option exercise | 5,698 | — | — | — | Aug 20, 2026 |
| Option exercise | 1,710 | — | — | — | Aug 20, 2026 |
| Option exercise | 1,512 | — | — | — | Aug 20, 2026 |
Listing the 25 most recent of 38 Form 4 filings held for STX; the 13 older filings (filed Jul 24 – Aug 24, 2026) are counted above but not listed here — see STX's full Form 4 filing history on SEC EDGAR.
Insider filings reported around the same time
Other companies whose most recent Form 4 was filed closest to STX's (Oct 2, 2026).
Frequently asked about STX insider activity
How many insiders bought STX stock in the last 90 days?
No open-market purchases (Form 4 code P) of STX shares were reported by Seagate Technology Holdings insiders in the trailing 90 days. The 38 filings shown on this page cover other transaction types — sales, grants, option exercises, and tax withholding.
Who filed the most recent Form 4 for STX?
The most recent Form 4 on this page was filed by William D. Mosley (CEO) on Oct 2, 2026, reporting 30 transactions. The original document is linked from the filing list above on SEC EDGAR. Amended filings (Form 4/A) may later revise reported figures.
What was the largest open-market STX insider sale shown?
The largest open-market sale among the filings shown was 97,889 STX shares at $772.14 (about $75,584,519) by William D. Mosley (CEO) on Sep 15, 2026. Value is shares × the price reported on the Form 4; its Rule 10b5-1 box is not checked.
New to Form 4s? The transaction codes, the 90-day window and the 0–100 score are defined on the insider-activity score methodology page.
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Track STX insider filings free →This score summarizes SEC Form 4 filing activity over the trailing 90 days. It is descriptive, not predictive — not a rating, recommendation, or investment advice. Data: SEC EDGAR (public domain), as filed; amendments may revise figures. Tradune is not a registered investment adviser.
Data as filed; amended filings (Form 4/A) may revise figures. Sales may occur under prearranged Rule 10b5-1 trading plans.