Avoid the stress of overpaying for a stock or missing an opportunity by using the right tools and insights to evaluate Quantum-Si incorporated before investing.

In this article, we go over a few key elements for understanding Quantum-Si incorporated’s stock price such as:

• Quantum-Si incorporated’s current stock price and volume
• Why Quantum-Si incorporated’s stock price changed recently
• Upgrades and downgrades for QSI from analysts
• QSI’s stock price momentum as measured by its relative strength

About Quantum-Si incorporated (QSI)

Before we jump into Quantum-Si incorporated’s stock price, history, target price and what caused it to recently dip, let’s take a look at some background.

Quantum-Si incorporated, a life sciences company, develops proprietary, universal, and single-molecule detection platform applied to proteomics to enable next-gen protein sequencing (NGPS). The company offers Platinum and Platinum Pro NGPS instruments for single-molecule, amino acid level resolution, and automated data analysis; library preparation kits to prepare a customer’s protein sample for sequencing; and sequencing kits, which contain the reagents and consumables used to perform NGPS. It also provides Platinum analysis software, a cloud-based solution that automates data analysis workflows and visualizes the sequencing results. The company was founded in 2013 and is headquartered in Branford, Connecticut.

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Quantum-Si incorporated’s Stock Price as of Market Close

As of June 09, 2026, 4:00 PM, CST, Quantum-Si incorporated’s stock price was $0.987.

Quantum-Si incorporated is down 6.88% from its previous closing price of $1.060.

During the last market session, Quantum-Si incorporated’s stock traded between $0.940 and $1.080. Currently, there are approximately 216.47 million shares outstanding for Quantum-Si incorporated.

Quantum-Si incorporated’s trailing earnings per share are negative, so the stock does not have a meaningful P/E ratio. We suggest investors evaluate other financial metrics to understand its overall valuation.

Quantum-Si incorporated Stock Price History

Quantum-Si incorporated’s (QSI) price is currently down 17.05% so far this month.

During the month of June, Quantum-Si incorporated’s stock price has reached a high of $1.300 and a low of $0.940.

Over the last year, Quantum-Si incorporated has hit prices as high as $3.100 and as low as $0.691. Year to date, Quantum-Si incorporated’s stock is down 10.26%.

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What Caused Quantum-Si incorporated Stock’s Price to Dip?

Stock prices are primarily based on seller supply and buyer demand. But have you ever wondered about what other factors affect a stock's price?

When an analyst changes their opinion of a stock by upgrading or downgrading their rating, it often leads to a sudden stock price adjustment. As of June 09, 2026, there were 0 analysts who downgraded Quantum-Si incorporated’s stock and 1 analyst who upgraded over the last month.

Additionally, you'll want to evaluate Quantum-Si incorporated’s financial health and valuation. Investors can use AAII's Value Grade, which combines six key valuation metrics like P/E and P/S ratios for a comprehensive analysis to conduct analysis on Quantum-Si incorporated’s valuation and financial health. This approach mitigates the limitations of single-metric evaluations.

Quantum-Si incorporated’s current valuation based on AAII’s Value Grade is a F, which means it is considered to be Ultra Expensive.

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Lastly, news and media coverage as well as recent press reports about the company or its industry may cause stock prices to fluctuate. You can check out the most recent news articles about Quantum-Si incorporated (QSI) by visiting AAII Stock Evaluator.

Relative Price Strength of Quantum-Si incorporated

Relative price strength measures a stock's performance against the market, helping investors identify stocks that are outperforming benchmarks.

For AAII’s Momentum Grade, a weighted relative price strength is calculated. Follow this link to learn more about the Momentum Grade.

As of June 09, 2026, Quantum-Si incorporated has a weighted four-quarter relative price strength of -14.50%, which translates to a Momentum Score of 18 and is considered to be Very Weak.

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Quantum-Si incorporated Stock Price: Bottom Line

As of June 9, 2026, Quantum-Si incorporated’s stock price is $0.987, which is down 6.88% from its previous closing price.

AAII advises against making stock decisions based solely on price or past returns. Instead, consider a variety of metrics, fundamentals, and analytics to evaluate a stock like Quantum-Si incorporated stock prices are influenced by market supply and demand and offer just a snapshot of a company's overall health.

Subscribing to AAII's A+ Investor provides access to comprehensive analytics and insights for confident investing.