MASSENGILL MATTHEW E Insider Trades at WESTERN DIGITAL CORP

Spot the Money

MASSENGILL MATTHEW E

Director at WESTERN DIGITAL CORP

Company: WESTERN DIGITAL CORP
Ticker: WDC
First filing on record: November 21, 2025
Latest trade on record: September 17, 2026
SEC filings: EDGAR ↗

MASSENGILL MATTHEW E, Director at WESTERN DIGITAL CORP, has disclosed 16 transactions in WDC since November 21, 2025: 0 purchases (0 open-market buys) and 11 sales, worth about $9.6M at the reported prices. The latest was filed September 21, 2026, 4 days after the trade; 1 filing was late against the 2-business-day Form 4 deadline.

Last updated September 21, 2026 · Source: SEC EDGAR Form 4 filings

Transactions

16

Open-market buys

0

Sales

11

Avg. disclosure lag

1.6d

Trading in charts

Trade timeline

When does this person trade, how big, and in which direction? Every trade in the last 12 months.

Bought (above the line)Sold (below the line)Other transaction

In the last 12 months MASSENGILL MATTHEW E made no purchases and 11 sales worth $9.6M, plus 5 other transactions. Dot size is the dollar amount.

Portfolio mix

Which stocks does this person trade most? Tile size is dollars traded, all time on record.

MASSENGILL MATTHEW E has traded 1 stock on record; the largest by dollars is WDC.

Reporting lag

Does this person report on time? One bar per filing against the Form 4 deadline.

On timeLate

1 of 6 filings on record were reported after the Form 4 deadline (two business days, counted here as 4 calendar days).

What kind of transactions

Most Form 4 rows are pay arriving or tax being withheld, not a decision to buy or sell. Only code P is an open-market purchase and code S an open-market sale. What each code means: Form 4 transaction codes.

Rows by Form 4 transaction code
Code	Meaning	Rows	Shares	Value
S	Open-market sale	11	36,926	$9.6M
A	Grant or award	5	1,634	—

Rows by year of the trade
Year	Rows	Bought	Sold
2026	14	0	11 · $9.6M
2025	2	0	0

Transactions

Download WDC trades (CSV)565 rows · 197 KB · every filer in this ticker, this insider included · all downloads

Security	Side	Trade date	Disclosed	Lag	Shares	Price	Value	Flags	Source
WDC	Other A	September 17, 2026	September 21, 2026	4d	10	—	—	derivative	Form 4 ↗
WDC	Other A	June 17, 2026	June 22, 2026	5d	6	—	—	late derivative	Form 4 ↗
WDC	Other A	March 18, 2026	March 19, 2026	1d	12	—	—	derivative	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	400	$268	$107K	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	916	$266	$244K	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	2,200	$265	$583K	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	2,600	$264	$686K	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	2,300	$263	$604K	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	3,597	$262	$941K	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	5,987	$261	$1.6M	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	4,915	$260	$1.3M	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	7,000	$259	$1.8M	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	4,411	$258	$1.1M	10b5-1 planindirect	Form 4 ↗
WDC	Sell S	February 5, 2026	February 6, 2026	1d	2,600	$257	$667K	10b5-1 planindirect	Form 4 ↗
WDC	Other A	December 18, 2025	December 22, 2025	4d	21	—	—	derivative	Form 4 ↗
WDC	Other A	November 20, 2025	November 21, 2025	1d	1,585	—	—		Form 4 ↗

Filings

Filed	Form	Accession	Rows	Status	Source
September 21, 2026	Form 4	0001266824-26-000208	1	published	EDGAR ↗
June 22, 2026	Form 4	0001266824-26-000152	1	published	EDGAR ↗
March 19, 2026	Form 4	0001266824-26-000064	1	published	EDGAR ↗
February 6, 2026	Form 4	0001266824-26-000008	11	published	EDGAR ↗
December 22, 2025	Form 4	0001266824-25-000287	1	published	EDGAR ↗
November 21, 2025	Form 4	0001266824-25-000230	1	published	EDGAR ↗

Other insiders at WESTERN DIGITAL CORP

Cole Martin I Director 116 rows
Tan Irving Chief Executive Officer 102 rows
Davis Brian Scott Chief Sales & Marketing Office 95 rows
Tregillis Cynthia L Chief Legal Officer & Corp Sec 84 rows
Gubbi Vidyadhara K Chief of Global Operations 65 rows
Shihab Ahmed Mohammed Chief Product Officer 17 rows
Sennesael Kris Chief Financial Officer 14 rows
Oulman Roxanne Director 13 rows
KIDDOO BRUCE E Director 11 rows
STREETER STEPHANIE A Director 10 rows

Everyone on file, with contracts and lobbying under the company's name: WESTERN DIGITAL CORP.

Guides for this page

What is SEC Form 4? Who files: officers, directors and owners of more than 10% of a class of the company's shares.
Form 4 transaction codes P = purchase. S = sale. These are the two market trades.
Insider buying vs insider selling Selling outweighs buying by a wide margin in normal times.
Rule 10b5-1 trading plans The plan must be set up when the insider has no important non-public information.
Options and derivatives on Form 4 Table I = shares. Table II = options and other derivatives.

Sources and method

Official sources behind this page
Source	Filings	Rows	First filed	Newest filed	Read the originals
SEC EDGAR, Form 4	6	16	November 21, 2025	September 21, 2026	Form 4 list on EDGAR

Site built October 22, 2026. Every row in the tables above links to its own filing. To quote a figure, use the Cite button at the top of the page; see how to cite and reuse.

Every row comes from the reporting owner's Form 4 as filed with the SEC (EDGAR ownership XML), read daily. "Value" is shares × the reported price; code P is an open-market purchase, S a sale, M an option exercise, A a grant. The lag is the filing date minus the trade date; Form 4 is due within two business days. Amendments (4/A) are not merged. Details on the methodology page; report an error on corrections.

Not investment advice. Figures are public disclosures shown as filed; they may lag the trade and may be amended later. No recommendation is made or implied.