$STX

$678.60 +$34.39 (5.34%) Live

$STX Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 226.6M shares outstanding

Who owns STX?

By type of holder

Institutions 82.8% Insiders 0.0% Everyone else 17.2%

Concentration Top 10 holders own 36.1%

BlackRock, Inc. 6.7% · Vanguard Capital Management LLC 6.5%

Institutional ownership

82.8%

-0.8 pts vs last qtr

Institutional holders

1,948

+493 vs last qtr

Net shares bought

−1.9M

by institutions in Q2 2026

New / sold out

582 / 89

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Norges Bank NEW +3.1M
Wellington Management Group LLP +2.3M

Biggest sellers in Q2 2026

Sanders Capital, LLC −9.4M
Vanguard Portfolio Management LLC −3.1M

Who is planning to sell?

Notices of proposed sale, last 12 months

$617M

69 notices from 16 people

Shares covered

892.8K

0.39% of the company

Arranged in advance

71%

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

William D. Mosley Director 10b5-1 $176M
Mosley William D Officer $103M

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2017–FY2026

−23.4%

−2.92% a year

Each share's claim on the business

+30.6%

grew without buying or selling a share

Spent on buybacks vs paid in stock

$7.06B vs $1.37B

over 10 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years63% 3–5 years8% 1–3 years12% Under 1 year17%

Quarterly turnover

16.8%

of institutional shares changed hands

Top 10 managers, median time held

5 years

Super Investors

Investment managers reporting STX on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
B BlackRock, Inc.	15.2M	6.69%	+892.7K (+6.3%)	≤2021	0.2%
Shares held by quarter Peak holding16.1M (Q4'25) Change over 8 quarters+1.3M Share of the company6.690% BlackRock, Inc.'s full portfolio →
VC Vanguard Capital Management LLC	14.6M	6.46%	+474.4K (+3.4%)	≤2021	0.3%
Shares held by quarter Peak holding14.6M (Q2'26) Change over 8 quarters+14.6M Share of the company6.460% Vanguard Capital Management LLC's full portfolio →

BlackRock, Inc.

15.2M

% of company

6.69%

Change vs last qtr

+892.7K (+6.3%)

Held since

≤2021

Vanguard Capital Management LLC

14.6M

% of company

6.46%

Change vs last qtr

+474.4K (+3.4%)

Held since

≤2021

28 more super investors behind a free account

See every manager holding Seagate Technology Holdings PLC, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting STX on Form N-PORT; together they hold 16.5% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
VT Vanguard Total Stock Market Index Fund Vanguard Index Funds	$6.87B	7.1M	3.14%	0.30%	June 30, 2026
V5 Vanguard 500 Index Fund Vanguard Index Funds	$5.61B	5.8M	2.57%	0.34%	June 30, 2026

Vanguard Total Stock Market Index Fund

Vanguard Index Funds

Position value

$6.87B

% of company

3.14%

% of the fund

0.30%

As of

June 30, 2026

Vanguard 500 Index Fund

Vanguard Index Funds

Position value

$5.61B

% of company

2.57%

% of the fund

0.34%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding Seagate Technology Holdings PLC and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
CM Cannon Michael R Insider	19.7K	0.01%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company0.010% Cannon Michael R's insider activity →
MW Mosley William D Insider	17.3K	0.01%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company0.010% Mosley William D's insider activity →

Cannon Michael R

Insider

19.7K

% of company

0.01%

Change vs last qtr

—

Held since

—

Mosley William D

Insider

17.3K

% of company

0.01%

Change vs last qtr

—

Held since

—

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