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Mark Mossler

CIK 1992219 · Chief Accounting Officer · last filed 2026-02-18

Mark Mossler is a Chief Accounting Officer who has filed 7 SEC Form 4 insider transactions across 1 company since 2024. The most recent filing, for CCCC, was dated Aug 14, 2026. Current disclosed insider exposure totals $282.7K 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

$282.7K

Companies

1

Total Filings

7

Lifetime Open-Market Net

$0

Filer Profile

Reported Address
C4 THERAPEUTICS, INC.
490 ARSENAL WAY, SUITE 120
WATERTOWN, MA 02472
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

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
CCCC Chief Accounting Officer 75,184 $3.76 $282.7K $0 3 2026-02-18

Recent Filings

7 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
2026-08-14 CCCC Notice (144) −4,139 -$17.6K EDGAR
2026-08-13 CCCC Notice (144) −15,000 -$61.1K EDGAR
2026-08-12 CCCC Notice (144) −19,519 -$76.7K EDGAR
2026-05-28 CCCC Notice (144) −9,087 -$35.5K EDGAR
2026-02-18 CCCC Mixed +63,132 -$6.2K EDGAR
2025-02-18 CCCC Tax (F) −1,586 -$5.0K EDGAR
2024-04-10 CCCC Grant (A) +18,290 $0 EDGAR
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.