Insider Trading March 24, 2026

Quantum-Si Product Chief Disposes of 21,997 Shares in Sell-to-Cover Transactions

John S. Vieceli sold roughly $18,416 of QSI stock across two trades tied to restricted stock unit tax withholdings

By Sofia Navarro QSI
Quantum-Si Product Chief Disposes of 21,997 Shares in Sell-to-Cover Transactions
QSI

John S. Vieceli, Chief Product Officer at Quantum-Si Inc., completed two sell-to-cover transactions on March 20 and March 23, 2026, disposing of 21,997 shares of Class A common stock for approximately $18,416. The sales were executed at weighted average prices of $0.8483 and $0.8266, respectively. The company recently reported mixed fourth-quarter 2025 results, beating EPS estimates but missing revenue forecasts, and an analyst trimmed its price target while keeping a Hold rating.

Key Points

  • John S. Vieceli sold 21,997 shares of Quantum-Si Class A common stock on March 20 and March 23, 2026, for about $18,416.
  • The transactions were executed to satisfy mandatory tax withholdings associated with vested restricted stock units; Vieceli now holds 1,170,657 shares directly.
  • Quantum-Si reported Q4 2025 EPS of -$0.08 (better than the -$0.12 estimate) but missed revenue at $451,000 versus a $761,900 forecast; Canaccord lowered its price target from $1.50 to $1.00 and kept a Hold rating.

John S. Vieceli, the Chief Product Officer at Quantum-Si Inc. (NASDAQ: QSI), executed two stock sales in late March 2026 that together totaled 21,997 shares of the companys Class A common stock.

The first transaction took place on March 20, when 10,758 shares were sold at a weighted average price of $0.8483, with execution prices spanning $0.8314 to $0.8718. The second transaction occurred on March 23, when 11,239 shares were sold at a weighted average price of $0.8266, with prices in the range of $0.7973 to $0.8525. Combined, the trades generated roughly $18,416 in proceeds.

Following these dispositions, Viecelis direct ownership stands at 1,170,657 shares of Quantum-Si. Company filings state that the sales were carried out under a mandatory sell-to-cover provision intended to satisfy required tax withholdings connected to the vesting of restricted stock units.

At the time of reporting, Quantum-Si shares were trading at $0.85, a level that represents a 42% decline over the past 12 months. Analysis provided by InvestingPro indicates the stock appears undervalued when measured against its Fair Value assessment. An InvestingPro note further flags the share price as quite volatile, with the companys beta recorded at 3.09. The InvestingPro platform also offers a Pro Research Report for QSI along with reports on more than 1,400 other U.S. equities.

These insider transactions come in the wake of Quantum-Sis fourth-quarter 2025 results, which delivered a mixed picture. The company reported earnings per share of -$0.08, outpacing analyst expectations of -$0.12. Revenue for the quarter amounted to $451,000, however, missing the forecasted $761,900.

In response to the quarter, Canaccord adjusted its price target for Quantum-Si shares from $1.50 to $1.00 and maintained a Hold rating. The analyst commentary attributed the adjustment to the companys weaker-than-expected quarterly performance. Canaccords note included detail on product sales, reporting that shipments of Platinum instruments were in the low-single-digit range and carried a gross margin of about 27%.

The transactions and the recent quarterly report together present a concise snapshot of recent insider activity and near-term performance metrics for Quantum-Si. The sale was processed under a prescribed tax-withholding mechanism linked to equity compensation vesting, while company results and analyst coverage provide context for current market valuation and sentiment.


Context and implications

The sell-to-cover trades by a senior product executive represent a routine liquidity event tied to equity compensation. At the same time, the firms most recent quarter combined an EPS beat with a revenue shortfall, prompting a notable analyst price-target reduction. Market indicators referenced in filings and third-party analysis point to elevated share volatility.

Risks

  • Equity volatility - InvestingPro notes the stock has a high beta of 3.09, indicating elevated price swings that affect investor risk in the biotech and broader capital markets sectors.
  • Revenue shortfall - The companys Q4 2025 revenue of $451,000 missed forecasts, which raises uncertainty about near-term commercial traction and affects the healthcare instruments market.
  • Analyst reassessment - Canaccords cut to a $1.00 price target reflects tempered expectations following the weaker quarter and may influence market sentiment in small-cap life sciences equities.

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