Quantum-SiQSI -4.98%29 PB Ratio is 0.85 as of Jun. 25, 2026, which is 10% below its 10-year median of 0.94. GuruFocus rates QSI with a GF Score™ of 29/100 and a GF Value™ of $0.84 (Fairly Valued). The stock has 4 warning signs investors should review. Among 788 Medical Devices & Instruments companies, Quantum-Si ranks better than 82.23% on this metric.
The PB Ratio, or Price-to-Book ratio, or Price/Book, is a financial ratio used to compare a company's market price to its Book Value per Share. As of today (2026-06-25), Quantum-Si's share price is $0.786. Quantum-Si's Book Value per Share for the quarter that ended in Mar. 2026 was $0.92. Hence, Quantum-Si's PB Ratio of today is 0.85.
The historical rank and industry rank for Quantum-Si's PB Ratio or its related term are showing as below:
QSI'
s PB Ratio Range Over the Past 10 Years
Min: 0.5 Med: 0.94 Max: 3.32
Current: 0.85
During the past 7 years, Quantum-Si's highest PB Ratio was 3.32. The lowest was 0.50. And the median was 0.94.
QSI's PB Ratio is ranked better than 82.23% of 788
companies
in the Medical Devices & Instruments industry
Industry Median: 2.045
vs QSI: 0.85
During the past 12 months, Quantum-Si's average Book Value Per Share Growth Rate was -31.40% per year.
During the past 3 years, the average Book Value Per Share Growth Rate was -26.50% per year.
During the past 7 years, the highest 3-Year average Book Value Per Share Growth Rate of Quantum-Si was -26.50% per year. The lowest was -28.00% per year. And the median was -27.25% per year.
The PB Ratio works the best for the businesses that earn most of their profit from their assets, e.g. banks and insurance companies.
Be Aware
Some businesses have very light assets, such as software companies or insurance agencies. The PB Ratio does not work well for these companies. Some companies even have negative equity, so the PB Ratio cannot be applied to them.
Quantum-Si PB Ratio Related Terms
Quantum-Si PB Ratio Historical Data
* Premium members only.
The historical data trend for Quantum-Si's PB Ratio can be seen below:
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
For the Medical Devices subindustry, Quantum-Si's PB Ratio, along with its competitors' market caps and PB Ratio data, can be viewed below:
* Competitive companies are chosen from companies within the same industry, with headquarter located in same country, with closest market capitalization; x-axis shows the market cap, and y-axis shows the term value; the bigger the dot, the larger the market cap. Note that "N/A" values will not show up in the chart.
Quantum-Si PB Ratio vs Medical Devices & Instruments Industry
For the Medical Devices & Instruments industry and Healthcare sector, Quantum-Si's PB Ratio distribution charts can be found below:
* The bar in red indicates where Quantum-Si's PB Ratio falls into.
The PB Ratio, or Price-to-Book ratio, or Price/Book, is a financial ratio used to compare a company's market price to its Book Value per Share. It is a ratio widely used to value stocks.
Quantum-Si's PB Ratio for today is calculated as follows:
* For Operating Data section: All numbers are indicated by the unit behind each term and all currency related amount are in USD. * For other sections: All numbers are in millions except for per share data, ratio, and percentage. All currency related amount are indicated in the company's associated stock exchange currency.
It can also be calculated from the numbers for the whole company:
A closely related ratio is called Price-to-Tangible-Book. The difference between Price-to-Tangible-Book and PB Ratio is that book value other than intangibles are used in the calculation.
Quantum-Si (QSI) has a PB Ratio of 0.85 as of Jun. 25, 2026. Price-to-Book ratio is the ratio of share price to a company's book value per share. View historical data on Quantum-Si and its competitors. This is 10% below median its historical median of 0.94. Over the past decade, Quantum-Si's PB Ratio has ranged from 0.50 to 3.32. According to the industry distribution chart, Quantum-Si ranks #140 out of 788 companies in the Medical Devices & Instruments industry, placing it in the top 17.8%.
Is Quantum-Si's PB Ratio too high?
Quantum-Si's current PB Ratio of 0.85 is 10% below median its 10-year median of 0.94. Over the past 10 years, this metric has ranged from a low of 0.50 to a high of 3.32. The Medical Devices & Instruments industry median PB Ratio is 2.05. Quantum-Si's value of 0.85 is 58.4% below this industry median. Based on the distribution chart, Quantum-Si ranks #140 out of 788 companies in the Medical Devices & Instruments industry, which is in the top quartile — a strong position relative to peers. Overall, Quantum-Si has a GF Score™ of 29/100 and is considered Fairly Valued, reflecting its overall financial health beyond just this single metric.
How does Quantum-Si's PB Ratio compare to SGHT and TMCI?
According to the Medical Devices & Instruments industry distribution chart, Quantum-Si ranks #140 out of 788 companies for PB Ratio. This places Quantum-Si in the top 18% of its industry — outperforming the majority of peers. The industry median PB Ratio is 2.05. Quantum-Si's value of 0.85 is 58.4% below this benchmark. Historically, Quantum-Si's own PB Ratio has ranged from 0.50 to 3.32 over the past decade. While the company's 10-year median is 0.94 vs. the industry median of 2.05, Quantum-Si has consistently been below the industry average. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good PB Ratio for a Medical Devices & Instruments company?
The median PB Ratio among Medical Devices & Instruments companies is 2.05, based on 788 companies in the industry. Companies in the top quartile (top 25%) have a PB Ratio significantly above this median, while those in the bottom quartile fall well below. However, PB Ratio should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Quantum-Si's current PB Ratio of 0.85 is 58.4% below the industry median. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high PB Ratio mean?
A high PB Ratio can signal that a stock is expensive relative to its fundamentals. Price-to-Book ratio is the ratio of share price to a company's book value per share. View historical data on Quantum-Si and its competitors. For the Medical Devices & Instruments industry, the median PB Ratio is 2.05 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Quantum-Si's current PB Ratio is 0.85, which is 10% below median its own 10-year median of 0.94. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Quantum-Si stock overvalued right now?
Based on GuruFocus' analysis, Quantum-Si (QSI) is currently considered Fairly Valued. The stock's GF Value™ is $0.84, compared to a current price of $0.79 — trading 6.4% below its estimated fair value. The current PB Ratio is 0.85, which is 10% below median its 10-year median of 0.94 and 58.4% below the Medical Devices & Instruments industry median of 2.05. Quantum-Si's overall GF Score™ is 29/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is PB Ratio calculated?
PB Ratio is calculated from a company's financial statements. For Quantum-Si (QSI), the current PB Ratio is 0.85 as of Jun. 25, 2026. GuruFocus calculates this using data sourced from SEC filings and annual reports. See the calculation section and 30-year financial data on this page for the full breakdown.
Is Quantum-Si (QSI) Overvalued in 2026?
Based on GuruFocus' analysis, Quantum-Si stock appears to be undervalued.
The current stock price of $0.79 is trading 6.4% below its estimated GF Value™ of $0.84.
GuruFocus considers Quantum-Si to be Fairly Valued.
Key valuation signals for QSI:
PB Ratio: 0.85 (10% below median its 10-year median of 0.94)
GF Value™: $0.84 vs. price of $0.79 (6.4% below fair value)
Industry Position: 58.4% below the Medical Devices & Instruments median (#140 of 788)
No single metric tells the full story. See the QSI stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Quantum-Si Inc is a life sciences company focused on proteomics research and analytical technologies. It develops single-molecule detection platforms designed to enable next-generation protein sequencing (NGPS) and large-scale protein analysis. Its technology supports massively parallel sequencing of proteins and can also be applied to the study of nucleic acids, providing tools for researchers and clinical applications in molecular analysis. The company's revenue is derived from sales of products and services.
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