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Heather L Mason

CIK 1432601 · Interim Executive Officer · last filed 2026-06-18

Heather L Mason is an Interim Executive Officer who has filed 65 SEC Form 4 insider transactions across 3 companies since 2008. The most recent filing, for IMTX, was dated Jun 18, 2026. Across all open-market trades the lifetime net is −$19.6M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $14.2M across reported positions.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$14.16M

Companies

3

Total Filings

65

Lifetime Open-Market Net

-$19.61M

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
IMTX Director — $9.75 — $0 1 2026-06-18
Assertio Holdings, Inc. (ASRT) Delisted Director 0 $23.50 $0 -$567.8K 16 2026-06-16
ABT Executive Vice President 129,064 $109.72 $14.16M -$19.04M 47 2017-07-05

Recent Filings

65 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-06-18 IMTX Grant (A) — $0 EDGAR
2026-06-16 Assertio Holdings, Inc. (ASRT) Delisted Mixed −27,610 $0 EDGAR
2026-05-15 Assertio Holdings, Inc. (ASRT) Delisted Gift (G) — $0 EDGAR
2026-05-06 Assertio Holdings, Inc. (ASRT) Delisted Grant (A) +4,851 $0 EDGAR
2025-05-09 Assertio Holdings, Inc. (ASRT) Delisted Grant (A) +53,750 $0 EDGAR
2024-11-19 Assertio Holdings, Inc. (ASRT) Delisted Buy (P) +75,000 $60.0K EDGAR
2024-06-06 Assertio Holdings, Inc. (ASRT) Delisted Buy (P) +25,000 $24.2K EDGAR
2024-01-04 Assertio Holdings, Inc. (ASRT) Delisted Grant (A) — $0 EDGAR
2023-05-22 Assertio Holdings, Inc. (ASRT) Delisted Sell (S) −89,286 -$652.0K EDGAR
2023-05-19 Assertio Holdings, Inc. (ASRT) Delisted Notice (144) −89,286 -$651.8K EDGAR
Showing 1–10 of 65
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Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.