Massivemarkets

SEC Form 4

Seagate Technology Holdings PLC (STX) insider trading

In the 12 months to Oct 24, 2026, 11 STX insiders reported open-market sales of $465.2M across 77 filings; no open-market purchases were filed.

Latest filing · Last 12 months · Source: SEC EDGAR · How we count

Open-market sales
$465.2M
77 filings · 11 insiders
Open-market purchases
$0
0 filings
Pre-arranged sales (10b5-1)
54 of 77
$391.7M of $465.2M sold (84%)

Who traded STX, and when

  • Sale
  • Sale, pre-arranged (10b5-1)

STX daily close from Oct 24, 2025 to Oct 23, 2026, between $223.00 and $1,094.04, last $630.49. 77 sale and 0 purchase filings by 11 insiders, marked at their filing dates. William D. Mosley, CEO: sold $226.8M across 21 filings, first filed Nov 5, 2025, last Oct 2, 2026. Gianluca Romano, EVP & CFO: sold $107.1M across 13 filings, first filed Nov 14, 2025, last Sep 15, 2026. Ban Seng Teh, EVP & Chief Commercial Officer: sold $88.9M across 14 filings, first filed Nov 5, 2025, last Sep 16, 2026. John Christopher Morris, EVP & CTO: sold $18.3M across 10 filings, first filed Dec 16, 2025, last Sep 22, 2026. James CI Lee, EVP & CLO: sold $12.1M across 6 filings, first filed Nov 12, 2025, last Aug 26, 2026. Kian Fatt Chong, EVP Global Operations: sold $4.4M across 2 filings, first filed Nov 3, 2025, last Feb 23, 2026. 5 others: sold $7.6M across 11 filings, first filed Nov 3, 2025, last Sep 3, 2026.

Largest mark · tap a row for others

Gianluca Romano · EVP & CFO

Filing 1 of 3 within a week · $43,189,011 total

Sale $1,162,156

1,348 shares

Filed Sep 11, 2026 · traded Sep 10

Close on filing date $830.17

STX daily closelast $630.49

William D. Mosley · CEO

$226.8M sold

Gianluca Romano · EVP & CFO

$107.1M sold

Ban Seng Teh · EVP & Chief Commercial Officer

$88.9M sold

John Christopher Morris · EVP & CTO

$18.3M sold

James CI Lee · EVP & CLO

$12.1M sold

Kian Fatt Chong · EVP Global Operations

$4.4M sold

5 others

$7.6M sold
One row per insider, smaller filers combined; marks sit at the SEC filing date, sized by dollar value.

Has Seagate Technology Holdings PLC's CEO sold stock?

Yes. William D. Mosley (CEO) sold 350,195 shares ($226.8M) between Nov 2025 and Oct 2026, $195.1M of it under a pre-arranged 10b5-1 plan.

Open-market trades

77 filings in the last 12 months
InsiderRoleSoldBoughtFilingsPre-arranged (10b5-1)Last filed
William D. MosleyCEO$226.8M—2186% of sales
Gianluca RomanoEVP & CFO$107.1M—1390% of sales
Ban Seng TehEVP & Chief Commercial Officer$88.9M—1481% of sales
John Christopher MorrisEVP & CTO$18.3M—1095% of sales
James CI LeeEVP & CLO$12.1M—672% of sales
Kian Fatt ChongEVP Global Operations$4.4M—2—
Shankar ArumugaveluDirector$2.4M—2—
Yolanda Lee ConyersDirector$1.8M—4100% of sales
Stephanie TileniusDirector$1.8M—2—
Prat BhattDirector$929.9K—1100% of sales
Jay L. GeldmacherDirector$750.8K—2—
Other insider activity (not market trades) · 158 records
  • Option exercises125 records
  • Tax withholding26 records
  • Tax withholding (sold to cover)7 records

Reported on Form 4 but not purchases or sales in the market, so not counted in the totals above.

Build this yourself

This page joins two Massive endpoints: Form 4 filings and daily prices. Ask an agent to watch for new filings:

Agent prompt

Using the Massive API (massive.com/docs/llms.txt), check Form 4 filings for STX every day with transaction_code=P and tell me when an insider files an open-market purchase, with their role, shares, price and the filing link.

How to read this page

Open-market purchase or sale
A buy or sell of the company's stock at market price. Grants, option exercises, shares withheld for tax, gifts and employee stock plan purchases are listed separately and not counted.
Pre-arranged (10b5-1)
The insider marked the filing as made under a trading plan set up in advance (SEC Rule 10b5-1). The mark covers the whole filing, and an unmarked filing may still be under a plan.
Filing date
Insiders have two business days to report a trade. Totals and the chart use the filing date, when the trade became public.