Atmus Filtration Technologies Inc. (ATMU) 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 Aug 18, 2026.
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- Filings shown
- 8
- Open-market buys
- 1
- Open-market sells
- 5
- Buys, 10b5-1 box not checked
- 1 of 1
Counts cover the 8 most recent Form 4 filings Tradune holds for ATMU (filed May 13 – Aug 18, 2026); the score below covers only the trailing 90 days (1 buy, 1 sell). No completed check of ATMU's Form 4 list on SEC EDGAR is on record yet; the latest ATMU filing Tradune holds was filed Aug 18, 2026. This is not guaranteed to be the complete record — see ATMU'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 2 filings Tradune holds for ATMU filed Aug 13 – Aug 18, 2026. Grants, exercises, tax withholding and the other Form 4 transaction codes are left out.
1 open-market sale by Rule 10b5-1 checkbox
- On filings with the 10b5-1 box checked
- 0 sales· 0 sh
- checkbox disclosed
- On filings with the box not checked
- 1 sale· 3,870 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 |
|---|---|---|---|---|---|
| Renee SwanChief People Officer | 0 | 1 | — | 3,870 | −$196,956 |
| Stephen E. MacadamDirector | 1 | 0 | 2,000 | — | +$99,551 |
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 ATMU
Insiders reported 1 open-market purchase of ATMU between May 13, 2026 and Aug 18, 2026, across 1 distinct buyer. The most recent purchase was reported by Stephen E. Macadam (Director) on Aug 12, 2026. Grants, option exercises, and tax-withholding transactions are excluded from these counts.
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 not checked | 3,870 | $50.89 | 46,875 | −7.6% | Aug 17, 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 purchase 10b5-1 box not checked | 2,000 | $49.78 | 40,588 | +5.2% | Aug 12, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 2,566 | $45.25 | 50,745 | −4.8% | Jun 1, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 5,132 | $45.25 | 75,804 | −6.3% | Jun 1, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 2,890 | $45.25 | 43,579 | −6.2% | Jun 1, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Open-market sale 10b5-1 box not checked | 25,652 | $45.25 | 363,024 | −6.6% | Jun 1, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award | 2,619 | — | 5,733 | +84% | May 12, 2026 |
| Transaction | Shares | Price | Held after | Change† | Date |
|---|---|---|---|---|---|
| Grant / award | 28,509 | — | 28,509 | — | May 12, 2026 |
Insider filings reported around the same time
Other companies whose most recent Form 4 was filed closest to ATMU's (Aug 18, 2026).
Frequently asked about ATMU insider activity
How many insiders bought ATMU stock in these Form 4 filings?
1 distinct insider at Atmus Filtration Technologies Inc. reported 1 open-market purchase (Form 4 code P) of ATMU shares between May 13, 2026 and Aug 18, 2026, the most recent filed by Stephen E. Macadam (Director) on Aug 12, 2026. Grants, option exercises, and tax-withholding transactions are excluded from these counts.
Who filed the most recent Form 4 for ATMU?
The most recent Form 4 on this page was filed by Renee Swan (Chief People Officer) on Aug 18, 2026, reporting 1 transaction. 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 ATMU insider sale shown?
The largest open-market sale among the filings shown was 25,652 ATMU shares at $45.25 (about $1,160,676) by Stephanie Disher (Chief Executive Officer) on Jun 1, 2026. Value is shares × the price reported on the Form 4; its Rule 10b5-1 box is not checked.
Do the recent ATMU insider purchases have the Form 4 10b5-1 box checked?
No. The one ATMU open-market purchase shown was reported with the Rule 10b5-1 box not checked. A blank box records what the filer disclosed; it does not prove that no plan exists. Latest: Stephen E. Macadam (Director) on Aug 12, 2026, 2,000 shares.
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 ATMU 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.