NASDAQ · Technology · Holders
Seagate Technology (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.
- Last confirmed price
- $660.81+3.41%
- Oct 19, 2026, 4:00 PM EDT · Prices may be delayed
Data dates
Prices as of Oct 19, 4:00 PM EDT · Fundamentals checked Oct 19, 8:07 PM EDT · Statement period ended Jul 3, 2026
Ownership read
STX insider transaction activity: Net selling.
Blackrock Inc. is the largest institutional holder. 62 classified sales and 0 classified purchases appear in the recent insider records. 46 transactions lack a reliable action code. Use the filters below to separate open-market activity from option exercises, gifts, awards, and tax withholding.
Insider flow
STX
Directional bars ignore awards, gifts, conversions, and tax withholding rows.
Top holder
15.17M
Blackrock Inc.
Insider transaction activity
Net selling
$515.42M sold / $0.0000 bought · 46 unclassified
Observations shown
130
10 holder / 120 insider
- Increased / initiated
- Unavailable
- Prior positions were not supplied
- Insider rows
- 120
- Transaction dates shown per row
Ownership concentration and transaction activity
- Top 10 reported holders
- 36.86% outstanding
- Changes with share-count history
- Prior-position data unavailable
- New / exited positions
- Prior-position data unavailable
- Largest increase with share-count history
- Prior share counts unavailable
These changes cover the holders shown. A holder missing from this list may still own shares. Compare positions from the same reporting quarters.
Net shares sold: 680,094
Sale-code S shares minus purchase-code P shares in this sample. Includes disclosed plans and unknown plan status; excludes grants, gifts, exercises and withholding. This is activity, not sentiment.
- Purchase / sale; plan unknown: 62
- Conversion / exercise: 12
- Other / unclassified: 46
Top 10 institutional holders
Seagate Technology (STX) institutional ownership
Ranked by reported share count, with position changes and separate position and filing dates where ownership data supplies them.
| # | Institution | % held | Shares | Position / filing date |
|---|---|---|---|---|
| 1 | 6.67% | 15.17M | Position as of Jun 30, 2026Filing date unknown | |
| 2 | 6.43% | 14.63M | Position as of Jun 30, 2026Filing date unknown | |
| 3 | 4.36% | 9.91M | Position as of Jun 30, 2026Filing date unknown | |
| 4 | 3.59% | 8.15M | Position as of Jun 30, 2026Filing date unknown | |
| 5 | 3.52% | 8.00M | Position as of Jun 30, 2026Filing date unknown | |
| 6 | 3.31% | 7.54M | Position as of Jun 30, 2026Filing date unknown | |
| 7 | WCM Investment Management, LLC | 2.34% | 5.32M | Position as of Jun 30, 2026Filing date unknown |
| 8 | 2.29% | 5.20M | Position as of Jun 30, 2026Filing date unknown | |
| 9 | 2.27% | 5.16M | Position as of Jun 30, 2026Filing date unknown | |
| 10 | 2.08% | 4.72M | Position as of Jun 30, 2026Filing date unknown |
Recent insider transactions
Seagate Technology (STX) Form 4 filings
Action codes are translated so open-market buys and sales are separate from awards, gifts, conversions, and tax withholding. Window: Feb 2, 2026–Sep 21, 2026 · 120 records.
| # | Insider | % company | Action | Shares | Price | Value | Transaction / filing |
|---|---|---|---|---|---|---|---|
| 1 | MORRIS JOHN CHRISTOPHER Chief Technology Officer | <0.01% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 9.35K | $877.91 | $8,211,951 | Sep 21, 2026Filing date unavailableOriginal filing link unavailable |
| 2 | MORRIS JOHN CHRISTOPHER Chief Technology Officer | <0.01% | ConversionConversion or exercise of derivative securities. Read alongside sale rows before treating it as bearish.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 915 | $158.40 | $144,936 | Sep 21, 2026Filing date unavailableOriginal filing link unavailable |
| 3 | MORRIS JOHN CHRISTOPHER Chief Technology Officer | <0.01% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 15.46K | $772.18 | $11,941,704 | Sep 15, 2026Filing date unavailableOriginal filing link unavailable |
| 4 | MOSLEY WILLIAM D Chief Executive Officer | 0.04% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 97.89K | $772.15 | $75,584,519 | Sep 15, 2026Filing date unavailableOriginal filing link unavailable |
| 5 | ROMANO GIANLUCA Chief Financial Officer | 0.02% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 49.98K | $772.17 | $38,595,124 | Sep 15, 2026Filing date unavailableOriginal filing link unavailable |
| 6 | TEH BAN-SENG Officer | 0.02% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 52.73K | $782.08 | $41,239,128 | Sep 15, 2026Filing date unavailableOriginal filing link unavailable |
| 7 | MORRIS JOHN CHRISTOPHER Chief Technology Officer | <0.01% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 492 | $782.42 | $384,952 | Sep 14, 2026Filing date unavailableOriginal filing link unavailable |
| 8 | MOSLEY WILLIAM D Chief Executive Officer | <0.01% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 1.87K | $781.54 | $1,460,696 | Sep 14, 2026Filing date unavailableOriginal filing link unavailable |
| 9 | ROMANO GIANLUCA Chief Financial Officer | <0.01% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 5.55K | $841.95 | $4,677,037 | Sep 14, 2026Filing date unavailableOriginal filing link unavailable |
| 10 | TEH BAN-SENG Officer | <0.01% | SaleOpen-market or direct sale reported on Form 4.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 989 | $779.00 | $770,431 | Sep 14, 2026Filing date unavailableOriginal filing link unavailable |
| 11 | MORRIS JOHN CHRISTOPHER Chief Technology Officer | 0.01% | UnclassifiedThe available record does not identify a purchase, sale, or other action. Do not infer a trade direction.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 30.13K | Not reported | Not reported | Sep 14, 2026Filing date unavailableOriginal filing link unavailable |
| 12 | CHONG KIAN FATT Officer | <0.01% | UnclassifiedThe available record does not identify a purchase, sale, or other action. Do not infer a trade direction.Transaction context
Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership. | 14.47K | Not reported | Not reported | Sep 14, 2026Filing date unavailableOriginal filing link unavailable |
Frequently asked
Questions about this quote
Who are the largest STX shareholders?
Blackrock Inc. is the largest reported institutional holder of STX, with 15.17 million shares, or about 6.67% of shares outstanding.
What does the institutional filing activity show for STX?
Seagate Technology has 10 institutional rows on file. Previous position sizes are unavailable, so increases and reductions cannot be determined.
What insider transactions are available for STX?
TECHi shows 120 dated STX insider transactions through Sep 21, 2026, with transaction types kept separate so administrative actions are not presented as open-market trades.
Are STX insiders buying or selling?
The displayed STX activity reads Net selling: 62 sales and 0 purchases. Other transaction types remain separate.
Who is the most active reported STX insider?
MOSLEY WILLIAM D has the largest absolute share movement in the displayed STX filing rows, totaling 678,194 shares. The action labels provide the transaction context.
What this page answers
Check who owns the float and whether insiders are active.
Explore Institutional concentration, insider transaction pattern, and float context.
Keep in mind Filings are delayed or transactions are administrative rather than economic.
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