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FormFactor Inc. (FORM) Institutional Ownership & Insider Trading History

Top FORM institutional shareholders, filing changes, and Form 4 insider activity with filters for buys, sales, option exercises, gifts, and tax withholding.

Section freshness

Prices as of Sep 28, 4:00 PM EDT · Fundamentals checked Sep 29, 8:34 AM EDT · Statements Jun 27, 2026

Ownership read

FORM insider transaction activity: Net selling.

Blackrock Inc. is the largest institutional holder. 45 sales and 0 purchases appear in the recent Form 4 filings. Use the filters below to separate open-market activity from option exercises, gifts, awards, and tax withholding.

Review insider tradesView institutions

Insider flow

FORM

Purchases0
Sales283.04K

Directional bars ignore awards, gifts, conversions, and tax withholding rows.

Top holder

10.48M

Blackrock Inc.

Insider transaction activity

Net selling

$23.81M sold / $0.0000 bought

Observations shown

103

10 holder / 93 insider

Holder rows
10
Yahoo Finance · Filing dates shown per row
Increased / initiated
2
8 decreased · provider-reported changes
Insider rows
93
Yahoo Finance · Filing dates shown per row

Ownership concentration and transaction activity

Top 10 reported holders
44.40% outstanding
Changes with share-count history
Prior-position data unavailable
New / exited positions
0 / 0 explicitly reported
Largest increase with share-count history
Prior share counts unavailable

Reported-holder cohort only; absence from a limited provider list does not establish an exit. Changes are provider-reported and are only comparable quarter over quarter when the position periods match.

Net shares sold: 283,038

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: 45
  • Other / unclassified: 33
  • Gift: 2
  • Grant: 13

Top 10 institutional holders

FormFactor Inc. (FORM) institutional ownership

Ranked by reported share count, with position changes and separate position and filing dates where ownership data supplies them.

FormFactor Inc. (FORM) institutional ownership
#Institution% heldSharesChange %Position / filing date
1
Blackrock Inc.
13.5%10.48M-14.40%Position as of Jun 30, 2026Filing date unknown
2
Vanguard Portfolio Management LLC
6.72%5.24M-10.85%Position as of Jun 30, 2026Filing date unknown
3
Earnest Partners LLC
4.83%3.76M-22.81%Position as of Jun 30, 2026Filing date unknown
4
Vanguard Capital Management LLC
4.51%3.52M+1.23%Position as of Jun 30, 2026Filing date unknown
5
State Street Corporation
3.31%2.58M-11.84%Position as of Jun 30, 2026Filing date unknown
6
Polar Capital Holdings PLC
2.75%2.15M-6.38%Position as of Jun 30, 2026Filing date unknown
7
Geode Capital Management, LLC
2.35%1.83M-16.22%Position as of Jun 30, 2026Filing date unknown
8
Bank of America Corporation
2.29%1.78M-28.11%Position as of Jun 30, 2026Filing date unknown
9
Primecap Management Company
2.17%1.69M-5.51%Position as of Jun 30, 2026Filing date unknown
10
Invesco Ltd.
2.02%1.58M+27.47%Position as of Jun 30, 2026Filing date unknown
Showing 10 of 10 matching institutional rows.

Recent insider transactions

FormFactor Inc. (FORM) Form 4 filings

Action codes are translated so open-market buys and sales are separate from awards, gifts, conversions, and tax withholding.

FormFactor Inc. (FORM) Form 4 insider transactions
#Insider% companyActionSharesTransaction date
1
SLESSOR MICHAEL D
Chief Executive Officer
0.02%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

17.51KSep 16, 2026
2
STEVEN-WAISS KELLEY
Director
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

2.10KSep 3, 2026
3
SLESSOR MICHAEL D
Chief Executive Officer
0.02%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

16.00KAug 14, 2026
4
SLESSOR MICHAEL D
Chief Executive Officer
0.19%OtherProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Other / unclassified
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

147.70KAug 7, 2026
5
SLESSOR MICHAEL D
Chief Executive Officer
0.01%OtherProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Other / unclassified
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

9.68KAug 6, 2026
6
MCKINNIS ARIC BRENDAN
Chief Financial Officer
<0.01%OtherProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Other / unclassified
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

1.62KAug 6, 2026
7
SLESSOR MICHAEL D
Chief Executive Officer
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

4.74KJul 15, 2026
8
ST DENNIS THOMAS
Director
<0.01%Stock GiftProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Gift
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

740Jun 16, 2026
9
ST DENNIS THOMAS
Director
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

2.80KJun 15, 2026
10
SLESSOR MICHAEL D
Chief Executive Officer
0.02%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

11.89KJun 10, 2026
11
MCKINNIS ARIC BRENDAN
Officer
<0.01%OtherProvider-supplied Form 4 action code. Review the original filing before making a trading judgment.
Transaction context
Classification:
Other / unclassified
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

773Jun 2, 2026
12
RHODES SHERI
Director
<0.01%SaleOpen-market or direct sale reported on Form 4.
Transaction context
Classification:
Purchase / sale; plan unknown
10b5-1:
Unknown; not supplied by provider
Holdings after:
Not reported
Position sold:
Not calculable
Filed:
Not reported

Position sold = shares sold ÷ (shares sold + holdings after). Separate accounts or security classes may not represent total beneficial ownership.

6.33KJun 2, 2026
Showing 12 of 93 matching Form 4 rows. Percent of company uses current shares outstanding.

Frequently asked

Common questions.

Who are the largest FORM shareholders?

Blackrock Inc. is the largest reported institutional holder of FORM, with 10.48 million shares, or about 13.45% of shares outstanding.

What does the institutional filing activity show for FORM?

FormFactor Inc. has 10 institutional rows on file: 2 increased or initiated positions and 8 reduced them.

What insider transactions are available for FORM?

TECHi shows 93 dated FORM insider transactions through Sep 16, 2026, with transaction types kept separate so administrative actions are not presented as open-market trades.

Are FORM insiders buying or selling?

The displayed FORM activity reads Net selling: 45 sales and 0 purchases. Other transaction types remain separate.

Who is the most active reported FORM insider?

SLESSOR MICHAEL D has the largest absolute share movement in the displayed FORM filing rows, totaling 510,219 shares. The action labels provide the transaction context.

All data sources

Search the dated figures used for this view. Each entry identifies its units, reporting period and calculation status.

How to use this page

Use this to check who owns the float and whether insiders are active.

Best for Institutional concentration, insider transaction pattern, and float context.

Weak when Filings are delayed or transactions are administrative rather than economic.

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