Formfactor Inc (FORM) insider trading
Recent insider transactions reported to the SEC on Form 4 — directors and officers buying or selling their own company’s stock. Sourced directly from public SEC filings, latest filed Oct 14, 2026.
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- Filings shown
- 9
- Open-market buys
- 0
- Open-market sells
- 19
Counts cover the 9 most recent Form 4 filings Tradune holds for FORM (filed Jul 16 – Oct 14, 2026); the score below covers only the trailing 90 days (0 buys, 13 sells). No completed check of FORM's Form 4 list on SEC EDGAR is on record yet; the latest FORM filing Tradune holds was filed Oct 14, 2026. This is not guaranteed to be the complete record — see FORM's full Form 4 filing history on SEC EDGAR.
Open-market activity, last 90 days
Purchases (Form 4 code P) and sales (code S) on the 8 filings Tradune holds for FORM filed Aug 7 – Oct 14, 2026. Grants, exercises, tax withholding and the other Form 4 transaction codes are left out.
13 open-market sales by Rule 10b5-1 checkbox
- On filings with the 10b5-1 box checked
- 12 sales· 44,610 sh
- checkbox disclosed
- On filings with the box not checked
- 1 sale· 2,100 sh
- not proof that no plan exists
- Not comparable
- 0 sales· 0 sh
- filed before Apr 1, 2023, or no checkbox value in the filing data
Counts are Form 4 lines as filed. The checkbox is one per filing, so every sale on a filing with the box checked is counted there even if only some of its transactions were under a plan; it records what the filer disclosed, and the three categories are not a judgement about why a sale was made.
| Insider | Buys | Sells | Shares bought | Shares sold | Value |
|---|---|---|---|---|---|
| Mike SlessorCEO | 0 | 12 | — | 44,610 | −$5,318,786 |
| Kelley Steven-WaissDirector | 0 | 1 | — | 2,100 | −$201,810 |
Value = shares × the price reported on each Form 4 (+ purchases, − sales); every open-market line in this window disclosed a price.
Summarises ~90 days of public SEC Form 4 activity — more distinct buyers, officer involvement and net buying score higher. A description of filing activity, not a rating or buy signal. How this score is computed →
How to read this: an open-market purchase (Form 4 code P) is a buy at the market price with the insider’s own money, as opposed to a grant, award or option exercise; an open-market sale is code S. When two or more distinct insiders report open-market purchases in the same 90-day window, this site labels that a cluster — a definition, not a forecast; see insider cluster buying. “Held after” is Form 4 Table I column 5; “Change” = shares ÷ holdings before the trade (held after − shares for an acquisition, held after + shares for a disposition).
Insider Buying at FORM
No open-market insider purchases (Form 4 code P) were reported for FORM between Jul 16, 2026 and Oct 14, 2026. The filings below may include other transaction types — sales, grants, option exercises, and tax withholding — shown for completeness; they are not open-market purchases.
Recent Form 4 filings
Source: SEC EDGAR Form 4 · transaction codes explained
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 1,200 | $125.92 | 455,596 | −0.3% | Oct 14, 2026 |
| Open-market sale 10b5-1 box checked | 7,703 | $125.36 | 456,796 | −1.7% | Oct 14, 2026 |
| Open-market sale 10b5-1 box checked | 2,195 | $124.23 | 464,499 | −0.5% | Oct 14, 2026 |
† change in this filer’s own reported holding line (Form 4 Table I, col. 5), not of total company ownership; small prior holdings produce large percentages, so under 100 shares the prior holding is shown instead.
“10b5-1 box checked” = the filer checked the Form 4 box stating that a transaction on the filing was made under a plan intended to satisfy Rule 10b5-1(c); “10b5-1 box not checked” = the box was left blank, which does not prove that no plan exists. The box applies to Form 4s filed from April 1, 2023; older filings, and boxes we could not read, carry no tag. What the 10b5-1 box means.
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 8,737 | $104.26 | 475,467 | −1.8% | Sep 16, 2026 |
| Open-market sale 10b5-1 box checked | 7,773 | $105.12 | 467,694 | −1.6% | Sep 16, 2026 |
| Open-market sale 10b5-1 box checked | 1,000 | $105.80 | 466,694 | −0.2% | Sep 16, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 2,100 | $96.10 | 24,426 | −7.9% | Sep 3, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 1,125 | $131.65 | 490,425 | −0.2% | Aug 14, 2026 |
| Open-market sale 10b5-1 box checked | 5,535 | $132.50 | 484,890 | −1.1% | Aug 14, 2026 |
| Open-market sale 10b5-1 box checked | 686 | $133.33 | 484,204 | −0.1% | Aug 14, 2026 |
| Open-market sale 10b5-1 box checked | 3,282 | $130.54 | 491,550 | −0.7% | Aug 14, 2026 |
| Open-market sale 10b5-1 box checked | 2,892 | $129.55 | 494,832 | −0.6% | Aug 14, 2026 |
| Open-market sale 10b5-1 box checked | 2,482 | $128.72 | 497,724 | −0.5% | Aug 14, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Tax withholding | 3,288 | $117.39 | 500,206 | −0.7% | Aug 7, 2026 |
| Grant / award Performance-based Restricted Stock Units | 141,792 | — | — | — | Aug 7, 2026 |
| Option exercise Performance-based Restricted Stock Units | 141,792 | — | — | — | Aug 7, 2026 |
| Option exercise Restricted Stock Units | 5,908 | — | — | — | Aug 7, 2026 |
| Option exercise | 141,792 | — | 576,494 | +33% | Aug 7, 2026 |
| Tax withholding | 78,908 | $117.39 | 497,586 | −14% | Aug 7, 2026 |
| Option exercise | 5,908 | — | 503,494 | +1.2% | Aug 7, 2026 |
| Grant / award Restricted Stock Units | 27,696 | — | — | — | Aug 6, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award Restricted Stock Units | 6,924 | — | — | — | Aug 6, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Tax withholding | 3,357 | $115.21 | 434,702 | −0.8% | Aug 6, 2026 |
| Option exercise | 6,031 | — | 438,059 | +1.4% | Aug 6, 2026 |
| Option exercise Restricted Stock Units | 6,031 | — | — | — | Aug 6, 2026 |
| Option exercise | 3,644 | — | 434,056 | +0.8% | Aug 5, 2026 |
| Option exercise Restricted Stock Units | 3,644 | — | — | — | Aug 5, 2026 |
| Tax withholding | 2,028 | $114.44 | 432,028 | −0.5% | Aug 5, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Option exercise Restricted Stock Units | 1,099 | — | — | — | Aug 6, 2026 |
| Tax withholding | 274 | $115.21 | 14,152 | −1.9% | Aug 6, 2026 |
| Option exercise | 1,099 | — | 14,426 | +8.2% | Aug 6, 2026 |
| Option exercise | 521 | — | 13,457 | +4.0% | Aug 5, 2026 |
| Tax withholding | 130 | $114.44 | 13,327 | −1.0% | Aug 5, 2026 |
| Option exercise Restricted Stock Units | 521 | — | — | — | Aug 5, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box checked | 1,650 | $117.39 | 432,456 | −0.4% | Jul 15, 2026 |
| Open-market sale 10b5-1 box checked | 170 | $119.08 | 431,580 | −0.0% | Jul 15, 2026 |
| Open-market sale 10b5-1 box checked | 300 | $120.58 | 431,280 | −0.1% | Jul 15, 2026 |
| Open-market sale 10b5-1 box checked | 868 | $121.30 | 430,412 | −0.2% | Jul 15, 2026 |
| Open-market sale 10b5-1 box checked | 1,041 | $116.56 | 434,106 | −0.2% | Jul 15, 2026 |
| Open-market sale 10b5-1 box checked | 706 | $118.21 | 431,750 | −0.2% | Jul 15, 2026 |
Insider filings reported around the same time
Other companies whose most recent Form 4 was filed closest to FORM's (Oct 14, 2026).
Frequently asked about FORM insider activity
How many insiders bought FORM stock in these Form 4 filings?
No open-market purchases (Form 4 code P) of FORM shares were reported by Formfactor Inc insiders between Jul 16, 2026 and Oct 14, 2026. The 9 filings shown on this page cover other transaction types — sales, grants, option exercises, and tax withholding.
Who filed the most recent Form 4 for FORM?
The most recent Form 4 on this page was filed by Mike Slessor (CEO) on Oct 14, 2026, reporting 3 transactions. The original document is linked from the filing list above on SEC EDGAR. Amended filings (Form 4/A) may later revise reported figures.
What was the largest open-market FORM insider sale shown?
The largest open-market sale among the filings shown was 7,703 FORM shares at $125.36 (about $965,648) by Mike Slessor (CEO) on Oct 14, 2026. Value is shares × the price reported on the Form 4; that Form 4 has the Rule 10b5-1 box checked.
New to Form 4s? The transaction codes, the 90-day window and the 0–100 score are defined on the insider-activity score methodology page.
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Track FORM insider filings free →This score summarizes SEC Form 4 filing activity over the trailing 90 days. It is descriptive, not predictive — not a rating, recommendation, or investment advice. Data: SEC EDGAR (public domain), as filed; amendments may revise figures. Tradune is not a registered investment adviser.
Data as filed; amended filings (Form 4/A) may revise figures. Sales may occur under prearranged Rule 10b5-1 trading plans.