Was Mike Slessor's FormFactor (FORM) share sale under a Rule 10b5-1 plan?

Yes. A footnote explains the sale occurred automatically under a Rule 10b5-1 trading plan. That plan was adopted on August 19, 2025, indicating the transactions were pre-arranged rather than newly decided at the time of sale.

FormFactor CEO sells 9,438 shares in planned trade

FORMFACTOR INC CEO Mike Slessor reported a sale of 9,438 shares of Common Stock.

Accepted by SEC EDGAR 05/14/2026 - 05:32 PM EDT

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Form Type

Rhea-AI Filing Summary

FORMFACTOR INC CEO Mike Slessor reported a sale of 9,438 shares of Common Stock. The Form 4 shows 12 open-market sale transactions on May 13, 2026, with reported per-share prices such as $136.15, $135.73, and $122.84.

A footnote states the sales occurred automatically under a pre-arranged Rule 10b5-1 trading plan adopted on August 19, 2025. After these transactions, Slessor directly holds 447,037 shares of FormFactor common stock.

Insider Trade Summary 10b5-1

Net Seller: 9,438 shares

Net Sell 12 txns

Insider SLESSOR MIKE

Role CEO

Sold 9,438 shs ($1.19M)

Type	Security	Shares	Price	Value
Sale	Common Stock	700	$122.84	$86K
Sale	Common Stock	1,300	$123.72	$161K
Sale	Common Stock	2,984	$124.71	$372K
Sale	Common Stock	1,388	$125.58	$174K
Sale	Common Stock	398	$126.59	$50K
Sale	Common Stock	100	$127.47	$13K
Sale	Common Stock	700	$128.52	$90K
Sale	Common Stock	700	$129.33	$91K
Sale	Common Stock	200	$130.57	$26K
Sale	Common Stock	200	$132.63	$27K
Sale	Common Stock	66	$135.73	$9K
Sale	Common Stock	702	$136.15	$96K

Holdings After Transaction: Common Stock — 447,037 shares (Direct)

Footnotes (8)

F1. The reported sale of shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted on August 19, 2025.
F2. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $122.23 through $123.19. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.
F3. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $123.28 through $124.17. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.
F4. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $124.22 through $125.20. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.
F5. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $125.26 through $126.04. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.
F6. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $126.37 through $127.14. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.
F7. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $128.37 through $129.07. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.
F8. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $129.22 through $129.42. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

Key Figures

Shares sold: 9,438 shares Number of sale transactions: 12 transactions Example sale price: $136.15 per share +3 more

6 metrics

Shares sold 9,438 shares Total Common Stock sold on May 13, 2026

Number of sale transactions 12 transactions Open-market sales of Common Stock on May 13, 2026

Example sale price $136.15 per share One reported weighted average sale price on May 13, 2026

Lowest reported range low $122.23 per share Low end of a price range from a sale footnote

Shares held after transactions 447,037 shares Directly owned Common Stock following the sales

Net share direction -9,438 shares Net-sell shares from transaction summary

Key Terms

Rule 10b5-1 trading plan, weighted average sale price, open-market sale, Common Stock, +1 more

5 terms

Rule 10b5-1 trading plan regulatory

"The reported sale of shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted on August 19, 2025."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average sale price financial

"Price represents the weighted average sale price for the transaction reported."

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Common Stock financial

""security_title": "Common Stock""

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

Form 4 regulatory

"INSIDER FILING DATA (Form 4):"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did FORM CEO Mike Slessor report?

Mike Slessor, CEO of FormFactor (FORM), reported selling 9,438 shares of Common Stock. The Form 4 lists 12 open-market sale transactions completed on May 13, 2026, all involving directly owned shares.

How many FormFactor (FORM) shares did the CEO sell in this Form 4?

The Form 4 reports that CEO Mike Slessor sold 9,438 shares of FormFactor Common Stock. These shares were sold across 12 separate open-market transactions, all dated May 13, 2026, according to the transaction summary data.

At what prices were the FormFactor CEO's shares sold?

Reported sale prices per share range from around $122 to about $136. Individual line items include weighted average prices such as $136.15, $135.73, $132.63, and $122.84, reflecting multiple open-market sales on the same trading day.

How many FormFactor shares does the CEO hold after this sale?

Following the reported transactions, the Form 4 shows Mike Slessor directly owning 447,037 shares of FormFactor Common Stock. This post-transaction holding figure is provided in the transaction detail fields as the total shares following the sale.

How many sale transactions are reported in this FormFactor Form 4 filing?

The transaction summary shows 12 sale transactions for FormFactor Common Stock. Each entry is coded "S" for an open-market or private sale, all dated May 13, 2026, and together they total 9,438 shares sold by the CEO.

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Form 4 Insider Transactions: What Each Field Means →

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SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

SLESSOR MIKE

(Last)

(First)

(Middle)

7005 SOUTHFRONT ROAD

(Street)

LIVERMORE

CALIFORNIA

94551

(City)

(State)

(Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
FORMFACTOR INC [ FORM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	CEO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/13/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/13/2026		S		700⁽¹⁾	D	$122.84⁽²⁾	455,775	D
Common Stock	05/13/2026		S		1,300⁽¹⁾	D	$123.72⁽³⁾	454,475	D
Common Stock	05/13/2026		S		2,984⁽¹⁾	D	$124.71⁽⁴⁾	451,491	D
Common Stock	05/13/2026		S		1,388⁽¹⁾	D	$125.58⁽⁵⁾	450,103	D
Common Stock	05/13/2026		S		398⁽¹⁾	D	$126.59⁽⁶⁾	449,705	D
Common Stock	05/13/2026		S		100⁽¹⁾	D	$127.47	449,605	D
Common Stock	05/13/2026		S		700⁽¹⁾	D	$128.52⁽⁷⁾	448,905	D
Common Stock	05/13/2026		S		700⁽¹⁾	D	$129.33⁽⁸⁾	448,205	D
Common Stock	05/13/2026		S		200⁽¹⁾	D	$130.57	448,005	D
Common Stock	05/13/2026		S		200⁽¹⁾	D	$132.63	447,805	D
Common Stock	05/13/2026		S		66⁽¹⁾	D	$135.73	447,739	D
Common Stock	05/13/2026		S		702⁽¹⁾	D	$136.15	447,037	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. The reported sale of shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted on August 19, 2025.

2. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $122.23 through $123.19. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

3. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $123.28 through $124.17. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

4. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $124.22 through $125.20. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

5. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $125.26 through $126.04. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

6. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $126.37 through $127.14. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

7. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $128.37 through $129.07. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

8. Price represents the weighted average sale price for the transaction reported. Price range of shares sold is $129.22 through $129.42. Reporting person undertakes to provide, upon request by the SEC staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

Remarks:

	/s/ Stan Finkelstein, Attorney-in-fact for Mike Slessor	05/14/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR