Shares outstanding are shares that have been authorized, issued, and purchased by investors and are held by them. Castle Biosciences's shares outstanding for the quarter that ended in Mar. 2026 was 30.3 Mil.
Castle Biosciences's quarterly shares outstanding
increased
from Dec. 2025 (29.7 Mil) to Mar. 2026 (30.3 Mil).
It means Castle Biosciencesissued new shares from Dec. 2025 to Mar. 2026 .
Castle Biosciences's annual shares outstanding
increased
from Dec. 2024 (28.5 Mil) to Dec. 2025 (29.7 Mil).
It means Castle Biosciencesissued new shares from Dec. 2024 to Dec. 2025 .
A company may buy back shares or issue shares in any fiscal period. If a company buys back shares, we should observe that the total number of shares decline. If the company issues new shares, the number of shares outstanding increases.
Usually the presence of treasury shares and a history of buyback are good indicators that company has competitive advantage. But studies have shown that companies usually buy back at wrong time. Buying back shares below its intrinsic value increases value for remaining shareholders. Buying back overvalued shares destroys value for existing shareholders.
Be Aware
Warren Buffett looks for consistency and upward long term trend. Because of share repurchase it is possible for net earnings trend to differ from EPS trend. He preferred net income over EPS. The companies with durable competitive advantage companies report higher % net earnings to total revenues.
Important: If a company is showing net earnings history greater than 20% on total revenues, it is probably benefiting from a long term competitive advantage.
If net earnings is less than 10%, likely to be in a highly competitive business.
Castle Biosciences Shares Outstanding (EOP) Related Terms
Castle Biosciences Shares Outstanding (EOP) Historical Data
* Premium members only.
The historical data trend for Castle Biosciences's Shares Outstanding (EOP) 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.
CSTL vs FLGT, MYGN, PRE: Shares Outstanding (EOP) Comparison
For the Diagnostics & Research subindustry, Castle Biosciences's Shares Outstanding (EOP), along with its competitors' market caps and Shares Outstanding (EOP) 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.
Castle Biosciences Shares Outstanding (EOP) vs Medical Diagnostics & Research Industry
For the Medical Diagnostics & Research industry and Healthcare sector, Castle Biosciences's Shares Outstanding (EOP) distribution charts can be found below:
* The bar in red indicates where Castle Biosciences's Shares Outstanding (EOP) falls into.
Shares outstanding are shares that have been authorized, issued, and purchased by investors and are held by them. They have voting rights and represent ownership in the corporation by the person that holds the shares. They should be distinguished from treasury shares, which are shares held by the corporation itself, having no exercisable rights.
Shares outstanding can be calculated as either basic or fully diluted. The fully diluted shares outstanding count includes diluting securities, such as options, warrants or convertibles.
What does a Shares Outstanding (EOP) of 30.3 Mil mean?
Castle Biosciences (CSTL) has a Shares Outstanding (EOP) of 30.3 Mil as of Mar. 2026. The total shares a company has outstanding, at period-end. View historical data on Castle Biosciences and its competitors.
Is Castle Biosciences' Shares Outstanding (EOP) too high?
Castle Biosciences' current Shares Outstanding (EOP) is 30.3 Mil. Overall, Castle Biosciences has a GF Score™ of 73/100 and is considered Modestly Undervalued, reflecting its overall financial health beyond just this single metric.
How does Castle Biosciences' Shares Outstanding (EOP) compare to FLGT and MYGN?
Castle Biosciences' Shares Outstanding (EOP) of 30.3 Mil can be compared against companies in the Medical Diagnostics & Research industry. See the competitive comparison table and distribution chart on this page for a detailed peer-by-peer breakdown.
What is a good Shares Outstanding (EOP) for a Medical Diagnostics & Research company?
A good Shares Outstanding (EOP) depends on the Medical Diagnostics & Research industry context. However, Shares Outstanding (EOP) should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Use the industry distribution chart on this page to see where any company falls relative to its peers.
What does a high Shares Outstanding (EOP) mean?
A high Shares Outstanding (EOP) can signal that a stock is expensive relative to its fundamentals. The total shares a company has outstanding, at period-end. View historical data on Castle Biosciences and its competitors. Castle Biosciences's current Shares Outstanding (EOP) is 30.3 Mil. However, context matters — high-growth companies often justify higher valuations. Always evaluate alongside other metrics like GF Score™ and GF Value™.
Is Castle Biosciences stock overvalued right now?
Based on GuruFocus' analysis, Castle Biosciences (CSTL) is currently considered Modestly Undervalued. The stock's GF Value™ is $29.16, compared to a current price of $24.21 — trading 17% below its estimated fair value. The current Shares Outstanding (EOP) is 30.3 Mil. Castle Biosciences' overall GF Score™ is 73/100 with 4 warning signs to review. Investors should evaluate multiple metrics — including profitability, growth, and financial strength — before making a decision.
How is Shares Outstanding (EOP) calculated?
Shares Outstanding (EOP) is calculated from a company's financial statements. For Castle Biosciences (CSTL), the current Shares Outstanding (EOP) is 30.3 Mil as of Mar. 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 Castle Biosciences (CSTL) Overvalued in 2026?
Based on GuruFocus' analysis, Castle Biosciences stock appears to be undervalued.
The current stock price of $24.21 is trading 17% below its estimated GF Value™ of $29.16.
GuruFocus considers Castle Biosciences to be Modestly Undervalued.
Key valuation signals for CSTL:
Shares Outstanding (EOP): 30.3 Mil
GF Value™: $29.16 vs. price of $24.21 (17% below fair value)
No single metric tells the full story. See the CSTL stock analysis page for a complete view including 30-year financials, guru trades, and insider activity.
Castle Biosciences Inc is a molecular diagnostics company. The group provides test solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus (BE), and uveal melanoma. The product portfolio of the company includes DecisionDx-Melanoma, a risk stratification gene expression profile (GEP) test; DecisionDx-SCC, a risk stratification test for cutaneous squamous cell carcinoma; MyPath Melanoma, a diagnostic GEP test for use in patients with difficult-to-diagnose melanocytic lesions; and TissueCypher, a test to predict future development of progression of high-grade dysplasia and/or esophageal cancer. The company derives revenues through the delivery of test reports for its molecular diagnostic tests.
73GF Score
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