Reporting owner · CIK 0002057088

Tregillis Cynthia L

SEC Form 4 history across 1 companies, 31 transactions and 6 filings.

CLO, CSChief Legal Officer & Corp SecWESTERN DIGITAL CORP
Open-market transaction mix0% buys0 buys · 8 sales
Latest filingSep 21, 2026, 10:36 PM

Available history · May 22, 2026 – Sep 17, 2026

Filings6Form 4 records
Buying$00 purchases
Selling$1.8M8 sales
Net value−$1.8MBuys minus sells · disclosed values

Latest insider transactions

Form 4 filings from available history.
Tregillis Cynthia L transactions · 20 per page
CompanyInsiderActivityDisclosed valueFiled (ET)
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSF · withholding10b5-1 detectedSEC filing ↗-$177kView disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSM · exercise10b5-1 detectedSEC filing ↗$0View disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSM · exercise10b5-1 detectedDerivative securitySEC filing ↗$0View disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSS · sale10b5-1 detectedSEC filing ↗-$235kView disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSF · withholding10b5-1 detectedSEC filing ↗-$415kView disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSM · exercise10b5-1 detectedSEC filing ↗$0View disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSM · exercise10b5-1 detectedDerivative securitySEC filing ↗$0View disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSS · sale10b5-1 detectedSEC filing ↗-$115kView disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSF · withholding10b5-1 detectedSEC filing ↗-$373kView disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSM · exercise10b5-1 detectedSEC filing ↗$0View disclosure →
WDCWESTERN DIGITAL CORP
Tregillis Cynthia LCLO · CSS · sale10b5-1 detectedSEC filing ↗-$150kView disclosure →
Open a transaction for shares, transaction date, ownership and the original SEC filing.

Latest Form 4 facts

Quick context from source filings

Latest open-market transaction

sale at WESTERN DIGITAL CORP on Sep 04, 2026 valued at $194,918.

Review SEC filing
Latest buy

No open-market insider purchase is available.

Latest sale

sale at WESTERN DIGITAL CORP on Sep 04, 2026 valued at $194,918.

Review SEC filing

Monthly open-market activity

Last 4 reported months · purchases and sales

View exact monthly values
MonthPurchasesSalesBuy valueSale valueNet value
May 202602$0.00$265,972.70-$265,972.70
Jun 202601$0.00$235,699.20-$235,699.20
Aug 202604$0.00$1,113,618.53-$1,113,618.53
Sep 202601$0.00$194,918.40-$194,918.40

Net value is disclosed purchases minus sales, not profit. A dash means the value is unavailable.

Ownership and transaction size

Ownership and ticket size

Average P/S size$226.3K
Median P/S size$204.7K
Direct31
Indirect0
Sep 17, 2026grant

Filing-only signals

Deterministic matches in this insider's history

Cluster Sellingpattern1Derivative Transactionfiling-context7Direct Ownershipfiling-context27Large Salesize2Repeat Sellerpattern510b5-1 Detectedfiling-context26

Associated companies

Companies in the disclosed reporting history

WESTERN DIGITAL CORPWDC · 51 transactions · latest Sep 21, 2026, 10:36 PM

Open-market buy performance

90-day forward return on this insider's open-market purchases

90d forward
No open-market purchases in available history

A 90-day purchase return requires an open-market buy. No eligible purchases are recorded in this history.

Disclosed ownership

How reported shareholdings evolved

Non-derivative shares held after reported transactions—not stock prices or a complete portfolio.

23 observations · May 22, 2026 – Sep 4, 2026. Window ends at the latest available report, not today.

Selected observation · Sep 4, 2026111,030 shares reported
Inspect transaction
View exact observations and source transactions
Transaction dateShares held afterFiledSource
May 22, 2026118,135May 27, 2026View transaction
May 25, 2026118,142May 27, 2026View transaction
May 25, 2026117,371May 27, 2026View transaction
May 27, 2026117,157May 27, 2026View transaction
Jun 3, 2026117,774Jun 5, 2026View transaction
Jun 3, 2026117,075Jun 5, 2026View transaction
Jun 5, 2026116,643Jun 5, 2026View transaction
Aug 20, 2026114,542Aug 24, 2026View transaction
Aug 20, 2026114,163Aug 24, 2026View transaction
Aug 21, 2026113,928Aug 24, 2026View transaction
Aug 21, 2026113,939Aug 24, 2026View transaction
Aug 21, 2026112,830Aug 24, 2026View transaction
Aug 24, 2026112,146Aug 24, 2026View transaction
Aug 25, 2026112,153Aug 28, 2026View transaction
Aug 25, 2026111,382Aug 28, 2026View transaction
Aug 25, 2026115,260Aug 28, 2026View transaction
Aug 26, 2026114,784Aug 28, 2026View transaction
Aug 26, 2026114,793Aug 28, 2026View transaction
Aug 26, 2026113,162Aug 28, 2026View transaction
Aug 27, 2026112,155Aug 28, 2026View transaction
Sep 3, 2026112,162Sep 9, 2026View transaction
Sep 3, 2026111,462Sep 9, 2026View transaction
Sep 4, 2026111,030Sep 9, 2026View transaction

Securities and direct/indirect ownership contexts are kept separate and never summed. Joint filings may associate the same disclosed row with multiple owners. Unknown values are omitted, not treated as zero. Lines connect observations for readability; they do not establish holdings between filings, cost basis, or current ownership. Amendments and stock splits require reviewing the source.

Tregillis Cynthia L Insider Activity FAQ

SEC Form 4 context

Who is Tregillis Cynthia L?

Tregillis Cynthia L is a reporting owner in SEC Form 4 filings with reporting owner CIK 0002057088.

Which companies has Tregillis Cynthia L reported transactions for?

WESTERN DIGITAL CORP

When was Tregillis Cynthia L's latest insider buy?

No open-market insider purchase is available for this period.

When was Tregillis Cynthia L's latest insider sale?

sale at WESTERN DIGITAL CORP on Sep 04, 2026 valued at $194,918.

Where can I see the original SEC filings?

Each transaction row links directly to the source SEC filing so the reported Form 4 details can be reviewed.

Are performance metrics included?

The profile shows average and median 90-day stock returns after open-market purchases when price coverage is available. These are unadjusted stock returns, not realized trading gains. Win rates, benchmark-adjusted returns and conviction scores are not calculated.