Spero TherapeuticsSPRO +4.70%55 PS Ratio is 2.49 as of Jun. 26, 2026, which is 47% below its 10-year median of 4.68. GuruFocus rates SPRO with a GF Score™ of 55/100 and a GF Value™ of $1.06 (Significantly Overvalued). The stock has 4 warning signs investors should review. Among 936 Biotechnology companies, Spero Therapeutics ranks better than 81.52% on this metric.
The PS Ratio, or Price-to-Sales ratio, or Price/Sales, is a financial ratio used to compare a company's market price to its Revenue per Share. As of today, Spero Therapeutics's share price is $2.115.
Spero Therapeutics's Revenue per Share for the trailing twelve months (TTM) ended in Mar. 2026 was $0.85. Hence, Spero Therapeutics's PS Ratio for today is 2.49.
Good Sign:
Spero Therapeutics Inc stock PS Ratio (=2.38) is close to 1-year low of 2.32.
The historical rank and industry rank for Spero Therapeutics's PS Ratio or its related term are showing as below:
SPRO'
s PS Ratio Range Over the Past 10 Years
Min: 0.57 Med: 4.68 Max: 3084
Current: 2.5
During the past 11 years, Spero Therapeutics's highest PS Ratio was 3084.00. The lowest was 0.57. And the median was 4.68.
SPRO's PS Ratio is ranked better than 81.52% of 936
companies
in the Biotechnology industry
Industry Median: 9.165
vs SPRO: 2.50
Spero Therapeutics Inc revenue per share has been in decline over the past 3 years.
During the past 12 months, the average Revenue per Share Growth Rate of Spero Therapeutics was 63.10% per year.
During the past 3 years, the average Revenue per Share Growth Rate was -7.90% per year.
During the past 5 years, the average Revenue per Share Growth Rate was 118.80% per year.
During the past 11 years, Spero Therapeutics's highest 3-Year average Revenue per Share Growth Rate was 433.90% per year. The lowest was -7.90% per year. And the median was 71.45% per year.
Back to Basics: PS Ratio
Spero Therapeutics (NAS:SPRO) PS Ratio Explanation
The PS Ratio is an excellent valuation indicator if you want to compare a stock with its historical valuation or with the stocks in the same industry. The PS Ratio works especially well when you want to compare the stock's current valuation with its historical valuation. The PS Ratio is a great valuation tool for evaluating cyclical businesses where the PE Ratio works poorly. It works the best when comparing the current valuation with the historical valuation because over time, a company's profit margin tends to revert to the mean.
When the PS Ratio is applied to the whole stock market, it can be used to evaluate the current market valuation and projected returns. In this case, the price is the total market cap of all stocks that are traded, and sales are the GDP of the country. This is how Warren Buffett estimates the broad market valuation and project future returns.
The PS Ratio does not tell you how cheap or expensive the stock is. It cannot be used to compare companies in different industries. It works better for companies within the same industry because these companies tend to have similar capital structures and profit margins. It works the best when comparing a company with itself in the past.
Spero Therapeutics PS Ratio Related Terms
Spero Therapeutics PS Ratio Historical Data
* Premium members only.
The historical data trend for Spero Therapeutics's PS 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 Biotechnology subindustry, Spero Therapeutics's PS Ratio, along with its competitors' market caps and PS 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.
Spero Therapeutics PS Ratio vs Biotechnology Industry
For the Biotechnology industry and Healthcare sector, Spero Therapeutics's PS Ratio distribution charts can be found below:
* The bar in red indicates where Spero Therapeutics's PS Ratio falls into.
The PS Ratio, or Price-to-Sales ratio, or Price/Sales, is a financial ratio used to compare a company's market price to its Revenue per Share. It is a ratio widely used to value stocks and it was first used by Ken Fisher.
Spero Therapeutics's Share Price of today is $2.115. Spero Therapeutics's Revenue per Share for the trailing twelve months (TTM) ended in Mar. 2026 adds up the quarterly data reported by the company within the most recent 12 months, which was $0.85.
* 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:
Spero Therapeutics (SPRO) has a PS Ratio of 2.49 as of Jun. 26, 2026. Price-to-Sales ratio is the ratio of share price to a company's revenue per share. View historical data on Spero Therapeutics and its competitors. This is 47% below median its historical median of 4.68. Over the past decade, Spero Therapeutics' PS Ratio has ranged from 0.57 to 3,084.00. According to the industry distribution chart, Spero Therapeutics ranks #173 out of 936 companies in the Biotechnology industry, placing it in the top 18.5%.
Is Spero Therapeutics' PS Ratio too high?
Spero Therapeutics' current PS Ratio of 2.49 is 47% below median its 10-year median of 4.68. Over the past 10 years, this metric has ranged from a low of 0.57 to a high of 3,084.00. The Biotechnology industry median PS Ratio is 9.17. Spero Therapeutics' value of 2.49 is 72.8% below this industry median. Based on the distribution chart, Spero Therapeutics ranks #173 out of 936 companies in the Biotechnology industry, which is in the top quartile — a strong position relative to peers. Overall, Spero Therapeutics has a GF Score™ of 55/100 and is considered Significantly Overvalued, reflecting its overall financial health beyond just this single metric.
How does Spero Therapeutics' PS Ratio compare to ORMP and PLYX?
According to the Biotechnology industry distribution chart, Spero Therapeutics ranks #173 out of 936 companies for PS Ratio. This places Spero Therapeutics in the top 19% of its industry — outperforming the majority of peers. The industry median PS Ratio is 9.17. Spero Therapeutics' value of 2.49 is 72.8% below this benchmark. Historically, Spero Therapeutics' own PS Ratio has ranged from 0.57 to 3,084.00 over the past decade. While the company's 10-year median is 4.68 vs. the industry median of 9.17, Spero Therapeutics 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 PS Ratio for a Biotechnology company?
The median PS Ratio among Biotechnology companies is 9.17, based on 936 companies in the industry. Companies in the top quartile (top 25%) have a PS Ratio significantly above this median, while those in the bottom quartile fall well below. However, PS Ratio should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Spero Therapeutics's current PS Ratio of 2.49 is 72.8% 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 PS Ratio mean?
A high PS Ratio can signal that a stock is expensive relative to its fundamentals. Price-to-Sales ratio is the ratio of share price to a company's revenue per share. View historical data on Spero Therapeutics and its competitors. For the Biotechnology industry, the median PS Ratio is 9.17 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Spero Therapeutics's current PS Ratio is 2.49, which is 47% below median its own 10-year median of 4.68. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Spero Therapeutics stock overvalued right now?
Based on GuruFocus' analysis, Spero Therapeutics (SPRO) is currently considered Significantly Overvalued. The stock's GF Value™ is $1.06, compared to a current price of $2.12 — trading 99.5% above its estimated fair value. The current PS Ratio is 2.49, which is 47% below median its 10-year median of 4.68 and 72.8% below the Biotechnology industry median of 9.17. Spero Therapeutics' overall GF Score™ is 55/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is PS Ratio calculated?
PS Ratio is calculated from a company's financial statements. For Spero Therapeutics (SPRO), the current PS Ratio is 2.49 as of Jun. 26, 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 Spero Therapeutics (SPRO) Overvalued in 2026?
Based on GuruFocus' analysis, Spero Therapeutics stock appears to be overvalued.
The current stock price of $2.12 is trading 99.5% above its estimated GF Value™ of $1.06.
GuruFocus considers Spero Therapeutics to be Significantly Overvalued.
Key valuation signals for SPRO:
PS Ratio: 2.49 (47% below median its 10-year median of 4.68)
GF Value™: $1.06 vs. price of $2.12 (99.5% above fair value)
Industry Position: 72.8% below the Biotechnology median (#173 of 936)
No single metric tells the full story. See the SPRO stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Spero Therapeutics Inc is a clinical-stage biopharmaceutical firm. It focuses on identifying, developing, and commercializing novel treatments for MDR (Multi-drug-resistant) bacterial infections and rare diseases. The company's product candidate, tebipenem pivoxil hydrobromide or tebipenem HBr, is designed to be an oral carbapenem-class antibiotic for use in adults to treat MDR Gram-negative infections. It is also developing SPR720, a novel oral antibiotic designed for the treatment of a rare, orphan disease caused by pulmonary non-tuberculous mycobacterial infections, or NTM disease. It is also focused on SPR206, a next-generation polymyxin investigational product candidate being developed as an IV-administered medicine to treat MDR Gram-negative infections in the hospital.
55GF Score
Get the complete analysis for SPRO
PS Ratio is just one metric. See GF Value™, 30-year financials, guru trades, warning signs, and more.
Quick Browse
Personalize
Premium Gurus 
Create New Portfolio
SPRO has been successfully added to your 
