Castle Biosciences, Inc (CSTL) Fair Value & Analysis
Healthcare · US · Market cap $641M
Castle Biosciences, Inc
CSTL · US
Fair value as of: Jul 15, 2026
From 9 valuation models · updated 26 days ago
Fair value updated Jul 15, 2026, revised from $23.92 to $14.77 (−38.3%) since Jun 24, 2026. Share price +35.5% over the past month.
Below-average quality, and screening another 54% overvalued on our models.
What matters now
- The price sits above even our optimistic bull case ($18.41). The favourable scenario is already priced in.
- Solid but not exceptional quality (46/100) and above fair value, neither a clear bargain nor a standout compounder.
Price vs Fair Value (5 years)
White line = price, green steps = our fair value per fiscal year, dashed = 300-day average. As of Jul 15, 2026.
How to read this chart
60‑month range $11.66 – $77.60 · fair‑value band $11.13 – $18.41 · the $32.03 price screens above the $14.77 fair value. Green steps = our fair value per fiscal year (point-in-time, no hindsight). Dashed = 300-day average. As of Jul 15, 2026.
Analysis
Castle Biosciences, Inc (CSTL) currently trades at $32.03, while our model-based Fair Value estimate is $14.77, implying the stock looks roughly 53.9% overvalued today. The Quality Score stands at 46/100 (below-average quality), in the Healthcare sector. Bear case: priced above our estimate, the market already discounts strong expectations. Bull case: above-average quality can justify a premium, the entry price still matters most (evidence: medium).
Over the trailing twelve months, Castle Biosciences, Inc generated revenue of $340M at a net margin of -3.8%. Revenue declined 4.9% year over year. It earns a return on equity of -2.9%. The balance sheet holds a net cash position of $79.8M. Fundamentals as of Jul 15, 2026
Our scenario range runs from $11.13 (bear case) to $18.41 (bull case); at $32.03, the current price sits above that range. Bear and bull are the same models run on conservative and optimistic assumptions (margins, growth, valuation multiples), so a plausible valuation range, not a price target. The share trades about 28% below its 52-week high and 120% above its 52-week low, currently above its 200-day average. For context, the median of 10 Healthcare peers we cover trades at -48% fair-value upside, at -54%, CSTL screens richer than that median.
Fair Value models
Each model estimates fair value its own way; the Fair Value above is the evidence-weighted blend. Evidence (0–100) measures how completely this model’s inputs are available: well-fed models carry more weight in the blend. The spread across models is intentional, each one stresses a different value driver; dividend models, for instance, come out structurally low when payout is small.
All 9 models by family
Widest divergence: Growth DCF ($23.54) versus Dividend Discount ($0.7100). Highest evidence: Growth DCF (80).
Key figures & financial health
More key figures
Figures from reported company fundamentals · as of Jul 15, 2026. TTM = trailing twelve months.
Quality Score breakdown
Of which business quality 51 · Market factors (momentum, volatility) 59
Non-valuation factor families (profitability, growth, cashflow, financial strength, momentum …), each academically grounded. Valuation itself sits in the Fair Value and is deliberately excluded here to avoid double-counting.
About the company
Castle Biosciences, Inc., a molecular diagnostics company, provides test solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus (BE), atopic dermatitis (AD), and uveal melanoma.
Full company description
Castle Biosciences, Inc., a molecular diagnostics company, provides test solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus (BE), atopic dermatitis (AD), and uveal melanoma. The company offers DecisionDx-Melanoma, a risk stratification gene expression profile (GEP) test that predicts the likelihood of a positive sentinel lymph node and the risk of metastasis for patients with invasive cutaneous melanoma; TissueCypher, a risk stratification spatialomics test to predict future development of high-grade dysplasia and/or esophageal cancer in patients with non-dysplastic, indefinite dysplasia, and low-grade dysplasia BE; AdvanceAD-Tx, a non-invasive GEP test which is designed to guide systemic treatment selection for patients aged 12 years and older with moderateto-severe AD; DecisionDx-SCC, a GEP test for cutaneous squamous cell carcinoma; and MyPath Melanoma, a diagnostic GEP test for use in patients with difficult-to-diagnose melanocytic lesions. It also provides DecisionDx-UM, a risk stratification GEP test that predicts the risk of metastasis for patients with uveal melanoma. The company offers its products to dermatology and gastroenterology markets. The company was incorporated in 2007 and is headquartered in Friendswood, Texas.
Company description, as reported by the company or data provider.
Revenue & earnings trend
FY2021 – FY2025 · reported fiscal years
Castle Biosciences, Inc reported revenue of $344M in FY2025 versus $94.1M in FY2021, a compound +38.3%/yr. Reported net income was −$24.2M in FY2025.
CSTL screens 54% overvalued. Compare with Thermo Fisher Scientific Inc →
Earlier news
External third-party headlines (Yahoo Finance, Reuters and others), not an editorial selection.
- Castle Biosciences raises 2026 revenue guidance to $365M-$375M as TissueCypher volume trends toward 50%-52% growth
- Castle Biosciences Q2 Earnings Call Highlights
- Castle Biosciences, Inc. (CSTL) Reports Q2 Loss, Tops Revenue Estimates
- Castle Biosciences, Inc. Q1 2026 Earnings Call Summary
Peer Group
Diagnostics & Research · 136 stocks
How this stock ranks against its industry: the green marker is this stock, the band is the typical 25–75% peer range, and the tick is the median.
Valuation Multiples vs Diagnostics & Research median · lower = cheaper
Snowflake
Five quick dimensions, each 0 to 100: VALUE (fair-value potential), FUTURE (revenue growth), PAST (return on equity), HEALTH (low debt), DIVIDEND (yield). Green = this stock, grey = typical sector peer.
VALUE 0: the price sits above our fair-value range.
Insider activity: 40/100
Values & ESG
Does this company touch areas you may want to avoid? The classification is inferred from sector and industry.
ESG scores are not available for this stock yet. Values and ESG data are contextual and can differ between providers.
Similar stocks
10 more Diagnostics & Research stocks, each showing price versus our Fair Value estimate (as of Jul 15, 2026).
| Stock | Price | Fair Value | vs Fair Value |
|---|---|---|---|
| Thermo Fisher Scientific Inc TMO | $543.19 | $308.19 | -43% |
| Danaher Corporation DHR | $199.66 | $103.88 | -48% |
| WuXi AppTec Co 2359 | HK$160.70 | HK$125.20 | -22% |
| Lonza Group LONN | CHF 567.80 | CHF 259.80 | -54% |
| IDEXX Laboratories, Inc IDXX | $567.44 | $255.77 | -55% |
| Agilent Technologies, Inc A | $131.46 | $62.70 | -52% |
| Waters Corporation WAT | $368.98 | $121.96 | -67% |
| IQVIA Holdings IQV | $207.85 | $134.18 | -35% |
| Integrated Diagnostics Holdings IDHC | $0.0050 | $0.0053 | +5% |
| Illumina, Inc ILMN | $186.65 | $95.51 | -49% |
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How we calculate Fair Value
Each company is valued through a stack of independent intrinsic-value models (DCF variants, residual-income, multiples and more), blended into one family-balanced consensus and weighted by how much trustworthy data backs it. A separate quality layer scores the fundamentals. Every input is real reported data, nothing guessed.
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