Vieceli John S. 4

What Happened

• John S. Vieceli, Chief Product Officer of Quantum-Si (QSI), reported two sales of company stock as sales (S) related to the vesting of restricted stock units. He disposed of 10,758 shares on 2026-03-20 at a weighted average price of $0.85 ($9,126) and 11,239 shares on 2026-03-23 at a weighted average price of $0.83 ($9,290), for a total of 21,997 shares sold and proceeds of about $18,416. These were sell transactions (routine tax-withholding activity) rather than purchases.

Key Details

• Transaction dates and reported prices:
  • 2026-03-20: 10,758 shares at $0.85 — proceeds $9,126.
  • 2026-03-23: 11,239 shares at $0.83 — proceeds $9,290.
• Total shares sold: 21,997; total reported proceeds: ~$18,416.
• Footnotes:
  • F1: Sales were mandatory "sell-to-cover" to satisfy required federal, state and local tax withholding on vested RSUs; the insider could not alter this provision.
  • F2/F3: Represent weighted-average sale price details; the shares were sold over price ranges (detailed per-footnote) and the issuer/SEC staff can provide the per-share breakdown on request.
• Filing and timeliness:
  • Period of report: 2026-03-20. Form 4 filed on 2026-03-24. The filing appears timely under the two-business-day reporting rule for the listed transactions.

Context

• These sales were tax-withholding actions tied to RSU vesting (not discretionary open-market liquidations intended as investment signals). For retail investors, mandatory sell-to-cover transactions are common and do not necessarily indicate management sentiment about the stock. The filing did not include the insider’s total shares owned after these transactions in the materials provided here.