Quantum-Si stock gains 3.47 percent as Q2 signals split

Published on 09/25/2026 at 12:37 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

Quantum-Si stock is tied to second-quarter revenue of USD 0.34 million versus USD 0.30 million consensus on August 13, 2026. Proteus detected 18 amino acids on September 15.

QSI, US7491641091, Illustration mit AI erstellt.

Quantum-Si stock (ISIN US7491641091) stood at USD 0.79 on Nasdaq on September 24, 2026, up 3.47 percent from the USD 0.76 prior close. The move came as investors weighed a second-quarter revenue beat against a delayed Proteus launch and recent insider sales.

Revenue beat met a delay

According to MarketBeat in its September 23, 2026 report, Quantum-Si reported second-quarter revenue of USD 0.34 million against a USD 0.30 million consensus estimate. The same report said adjusted earnings per share were negative USD 0.11, matching consensus, for the quarter reported on August 13, 2026.

The revenue comparison is positive in absolute terms, but the scale remains small: the USD 0.34 million result exceeded the USD 0.30 million estimate by USD 0.04 million. MarketBeat also cited a negative net margin of 6,138.26 percent, underscoring that revenue growth alone does not yet resolve the company's profitability challenge.

Proteus reaches 18 amino acids

Quantum-Si demonstrated detection of 18 amino acids using a developmental sequencing kit on integrated Proteus instruments on September 15, 2026, according to Stock Titan. The company continues to target demonstration of all 20 amino acids during 2026.

The technical milestone is paired with a longer commercial timetable. The Proteus launch was shifted to the second quarter of 2027 after an additional integrated instrument design cycle, making execution against that date a central operating checkpoint.

Stock remains near yearly low

At USD 0.79 on September 24, 2026, Quantum-Si stock was USD 0.10 above its 52-week low of USD 0.69 and USD 2.31 below its 52-week high of USD 3.10. The current level leaves the shares 74.52 percent below the yearly high, while the market capitalization was USD 155.29 million.

Recent insider transactions add a separate signal. Investing.com reported that CFO Jeffry R. Keyes sold 7,665 shares on September 21 and September 22, 2026, in mandatory sell-to-cover transactions tied to restricted stock unit tax withholding.

Nasdaq price and valuation

Quantum-Si stock was trading at USD 0.79 on Nasdaq on September 24, 2026, with volume of 1,570,482 shares. Its 52-week range was USD 0.69 to USD 3.10, placing the current quote closer to the low than the high and keeping product execution central to the equity story.