Castle BiosciencesCSTL +6.07%73 Days Inventory is 46.03 as of Mar. 2026, which is 5% below its 10-year median of 48.37. GuruFocus rates CSTL with a GF Score™ of 73/100 and a GF Value™ of $29.16 (Modestly Undervalued). The stock has 4 warning signs investors should review. Among 176 Medical Diagnostics & Research companies, Castle Biosciences ranks better than 67.61% on this metric.
The historical rank and industry rank for Castle Biosciences's Days Inventory or its related term are showing as below:
CSTL'
s Days Inventory Range Over the Past 10 Years
Min: 22.62 Med: 48.37 Max: 65.09
Current: 43.29
During the past 9 years, Castle Biosciences's highest Days Inventory was 65.09. The lowest was 22.62. And the median was 48.37.
CSTL's Days Inventory is ranked better than 67.61% of 176
companies
in the Medical Diagnostics & Research industry
Industry Median: 68.88
vs CSTL: 43.29
Castle Biosciences's Days Inventory
increased
from Mar. 2025 (41.73) to Mar. 2026 (46.03).
It might indicate that Castle Biosciences's sales slowed down.
Inventory Turnover measures how fast the company turns over its inventory within a year.
Castle Biosciences's Inventory Turnover for the
three
months ended in Mar. 2026 was 1.98.
Inventory-to-Revenue determines the ability of a company to manage their inventory levels. It measures the percentage of Inventories the company currently has on hand to support the current amount of Revenue.
Castle Biosciences's Inventory-to-Revenue for the
three
months ended in Mar. 2026 was 0.12.
Castle Biosciences (NAS:CSTL) Days Inventory Explanation
Days Inventory indicates the liquidity of the inventory. Generally, a lower Days Inventory is preferred as it indicates a shorter duration to clear off the inventory. An increase of the ratio may indicate the company's sales slowed. Similar ratios related to Days Inventory are:
1. Inventory Turnover measures how fast the company turns over its inventory within a year.
Castle Biosciences's Inventory Turnover for the
three
months ended in Mar. 2026 is calculated as
2. Inventory-to-Revenue determines the ability of a company to manage their inventory levels. It measures the percentage of Inventories the company currently has on hand to support the current amount of Revenue.
Castle Biosciences's Inventory to Revenue for the
three
months ended in Mar. 2026 is calculated as
* 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.
Be Aware
A lot of business are seasonable. It makes more sense to compare Days Inventory from the same period in the previous year instead of from the previous quarter.
Castle Biosciences Days Inventory Related Terms
Castle Biosciences Days Inventory Historical Data
* Premium members only.
The historical data trend for Castle Biosciences's Days Inventory 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: Days Inventory Comparison
For the Diagnostics & Research subindustry, Castle Biosciences's Days Inventory, along with its competitors' market caps and Days Inventory 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 Days Inventory vs Medical Diagnostics & Research Industry
For the Medical Diagnostics & Research industry and Healthcare sector, Castle Biosciences's Days Inventory distribution charts can be found below:
* The bar in red indicates where Castle Biosciences's Days Inventory falls into.
* 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.
Castle Biosciences (CSTL) has a Days Inventory of 46.03 as of Mar. 2026. Days inventory represents the average amount of days a company holds inventory before selling it. View historical data on Castle Biosciences and its competitors. This is near median its historical median of 48.37. Over the past decade, Castle Biosciences' Days Inventory has ranged from 22.62 to 65.09. According to the industry distribution chart, Castle Biosciences ranks #57 out of 176 companies in the Medical Diagnostics & Research industry, placing it in the top 32.4%.
Is Castle Biosciences' Days Inventory too high?
Castle Biosciences' current Days Inventory of 46.03 is near median its 10-year median of 48.37. Over the past 10 years, this metric has ranged from a low of 22.62 to a high of 65.09. The Medical Diagnostics & Research industry median Days Inventory is 68.88. Castle Biosciences' value of 46.03 is 33.2% below this industry median. Based on the distribution chart, Castle Biosciences ranks #57 out of 176 companies in the Medical Diagnostics & Research industry, which is above the industry midpoint. 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' Days Inventory compare to FLGT and MYGN?
According to the Medical Diagnostics & Research industry distribution chart, Castle Biosciences ranks #57 out of 176 companies for Days Inventory. This puts Castle Biosciences in the upper half of its industry. The industry median Days Inventory is 68.88. Castle Biosciences' value of 46.03 is 33.2% below this benchmark. Historically, Castle Biosciences' own Days Inventory has ranged from 22.62 to 65.09 over the past decade. While the company's 10-year median is 48.37 vs. the industry median of 68.88, Castle Biosciences 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 Days Inventory for a Medical Diagnostics & Research company?
The median Days Inventory among Medical Diagnostics & Research companies is 68.88, based on 176 companies in the industry. Companies in the top quartile (top 25%) have a Days Inventory significantly above this median, while those in the bottom quartile fall well below. However, Days Inventory should not be evaluated in isolation — investors should consider it alongside profitability, growth, and financial strength metrics. Castle Biosciences's current Days Inventory of 46.03 is 33.2% 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 Days Inventory mean?
A high Days Inventory can signal that a stock is expensive relative to its fundamentals. Days inventory represents the average amount of days a company holds inventory before selling it. View historical data on Castle Biosciences and its competitors. For the Medical Diagnostics & Research industry, the median Days Inventory is 68.88 — values significantly above this may indicate overvaluation, while values below may suggest a bargain or underlying issues. Castle Biosciences's current Days Inventory is 46.03, which is near median its own 10-year median of 48.37. 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 Days Inventory is 46.03, which is near median its 10-year median of 48.37 and 33.2% below the Medical Diagnostics & Research industry median of 68.88. 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 Days Inventory calculated?
Days Inventory is calculated from a company's financial statements. For Castle Biosciences (CSTL), the current Days Inventory is 46.03 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:
Days Inventory: 46.03 (near median its 10-year median of 48.37)
GF Value™: $29.16 vs. price of $24.21 (17% below fair value)
Industry Position: 33.2% below the Medical Diagnostics & Research median (#57 of 176)
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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