Quantum-Si incorporated (QSI) Stock Price History
Historical prices from 2020 to 2026
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QSI Historical Performance
Short-Term Returns
QSI Stock Price Trajectory (2020–2026)
As of May 8, 2026, Quantum-Si incorporated (QSI) trades at $0.98, representing a -18.3% return over the past year. The stock has delivered a -90.6% total return over five years (-37.6% CAGR), reflecting challenging market conditions.
The stock reached its all-time high of $25.00 on February 18, 2021. From this peak, QSI has corrected -96.1%, currently trading 23% below its 200-day moving average, suggesting potential weakness.
When compared to Healthcare sector peers PACB (+46.0% 1Y), CDNA (+45.2% 1Y), and ACMR (+195.6% 1Y), QSI has underperformed the peer group average. Compare QSI vs PACB →
QSI Historical Price Data (2025–2026)
Showing 30 of 1,376 recordsLoading full history…
| Date | Open | High | Low | Close | Volume | Change % |
|---|---|---|---|---|---|---|
| 2026-05-07 | 1.03 | 1.03 | 0.96 | 0.98 | 7.04M | -4.80% |
| 2026-05-06 | 0.97 | 1.04 | 0.96 | 1.03 | 7.85M | +7.15% |
| 2026-05-05 | 0.98 | 0.98 | 0.95 | 0.96 | 2.48M | -1.05% |
| 2026-05-04 | 0.95 | 0.98 | 0.94 | 0.97 | 2.86M | +1.39% |
| 2026-05-01 | 0.98 | 1.00 | 0.94 | 0.96 | 3.56M | -2.28% |
| 2026-04-30 | 0.88 | 1.02 | 0.88 | 0.98 | 11.69M | +13.39% |
| 2026-04-29 | 0.90 | 0.90 | 0.86 | 0.86 | 3.40M | -5.18% |
| 2026-04-28 | 0.89 | 0.94 | 0.89 | 0.91 | 3.07M | +1.30% |
| 2026-04-27 | 0.91 | 0.94 | 0.87 | 0.90 | 3.08M | -0.61% |
| 2026-04-24 | 0.98 | 0.98 | 0.90 | 0.91 | 7.23M | -3.70% |
| 2026-04-23 | 1.02 | 1.04 | 0.92 | 0.94 | 7.24M | -11.26% |
| 2026-04-22 | 0.99 | 1.07 | 0.96 | 1.06 | 10.99M | +8.50% |
| 2026-04-21 | 1.00 | 1.05 | 0.97 | 0.98 | 5.09M | -3.27% |
| 2026-04-20 | 1.02 | 1.06 | 0.98 | 1.01 | 7.67M | -5.61% |
| 2026-04-17 | 1.06 | 1.14 | 1.06 | 1.07 | 6.89M | +2.88% |
| 2026-04-16 | 1.08 | 1.09 | 1.00 | 1.04 | 7.34M | -0.95% |
| 2026-04-15 | 0.90 | 1.06 | 0.90 | 1.05 | 17.21M | +24.88% |
| 2026-04-14 | 0.81 | 0.86 | 0.80 | 0.84 | 2.96M | +6.61% |
| 2026-04-13 | 0.73 | 0.80 | 0.72 | 0.79 | 2.56M | +6.51% |
| 2026-04-10 | 0.75 | 0.77 | 0.73 | 0.74 | 1.86M | -0.86% |
| 2026-04-09 | 0.75 | 0.76 | 0.73 | 0.75 | 2.61M | -0.48% |
| 2026-04-08 | 0.78 | 0.78 | 0.74 | 0.75 | 3.14M | +5.50% |
| 2026-04-07 | 0.73 | 0.73 | 0.69 | 0.71 | 3.25M | -2.43% |
| 2026-04-06 | 0.76 | 0.77 | 0.73 | 0.73 | 1.84M | -2.50% |
| 2026-04-02 | 0.73 | 0.76 | 0.72 | 0.75 | 2.54M | +0.03% |
| 2026-04-01 | 0.79 | 0.80 | 0.75 | 0.75 | 2.31M | -3.41% |
| 2026-03-31 | 0.76 | 0.80 | 0.76 | 0.77 | 2.74M | +4.91% |
| 2026-03-30 | 0.76 | 0.78 | 0.73 | 0.74 | 3.73M | -3.44% |
| 2026-03-27 | 0.79 | 0.82 | 0.76 | 0.76 | 3.10M | -5.52% |
| 2026-03-26 | 0.86 | 0.86 | 0.81 | 0.81 | 2.60M | -6.51% |
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Start ComparisonQSI — Frequently Asked Questions
Quick answers to the most common questions about buying QSI stock.
How has QSI stock performed recently?
QSI declined -18.3% over the past year, below its 5-year annualized CAGR of -37.6%. The stock trades below its 200-day moving average, reflecting the downtrend.
What is QSI's all-time high price?
Quantum-Si incorporated reached $25.00 on 2021-02-18. The 52-week high is $3.10. Current 1-year return of -18.3% places the stock further from historical peaks.
Where can I download QSI historical price data?
This page provides QSI daily OHLCV data with 50-day MA, 200-day MA, and RSI indicators. Data spans 2020-2026, downloadable in CSV format.