MOSSLER MARK

PrivateCIK: 1992219
Location

WATERTOWN, MA

Senior insider sale

Chief Accounting Officer at C4 THERAPEUTICS, INC. — senior position signals high conviction

$173.2K

43.61K shares

What this filing means

MOSSLER MARK plans to sell 43.61K shares of C4 THERAPEUTICS, INC. valued at approximately $173.2K. Form 144 is a notice of intent to sell restricted or control securities — not a mandatory transaction. This filing provides advance warning of potential selling pressure.

InsiderMOSSLER MARKCIK 1992219
IssuerC4 THERAPEUTICS, INC.CIK 1662579
Officer· Chief Accounting Officer
Since Feb 2026
43.61K
Shares to sell
$173.2K
Approx. market value
15K
Acquired (3 months)
1
Planned
2 completed
Securities Acquired — Last 3 Months1
Sort

Stock Option Exercise

Cash

8/13/2026
15K
Total acquired15K
Planned & Completed Dispositions3
Sort

Completed

Completed

Units to sell

19.52K

Market value

$76.7K

8/12/2026
Completed

Units to sell

9.09K

Market value

$35.5K

5/27/2026

Planned — Approximate Date

NASDAQPlanned

Units to sell

15K

Market value

$61.1K

8/13/2026
Total

Units

43.61K

Value

$173.2K