(CSTL) Castle Biosciences - Overview

Sector: Healthcare | Industry: Diagnostics & Research | Exchange: NASDAQ (USA) | Market Cap: 608m USD | Total Return: 24.6% in 12m

Molecular Diagnostics, Genetic Tests, Cancer Screening, Treatment Guidance
Total Rating 36
Safety 46
Buy Signal -0.84
Diagnostics & Research
Industry Rotation: +1.9
Market Cap: 608M
Avg Turnover: 9.84M
Risk 3d forecast
Volatility64.9%
VaR 5th Pctl9.66%
VaR vs Median-12.7%
Reward TTM
Sharpe Ratio0.56
Rel. Str. IBD8
Rel. Str. Peer Group5.8
Character TTM
Beta0.030
Beta Downside0.003
Hurst Exponent0.451
Drawdowns 3y
Max DD57.83%
CAGR/Max DD-0.13
CAGR/Mean DD-0.29
EPS (Earnings per Share) EPS (Earnings per Share) of CSTL over the last years for every Quarter: "2021-03": -0.17, "2021-06": -0.34, "2021-09": -0.47, "2021-12": -0.25, "2022-03": -0.97, "2022-06": -0.06, "2022-09": -0.77, "2022-12": -0.78, "2023-03": -1.1, "2023-06": -0.7, "2023-09": -0.26, "2023-12": -0.1, "2024-03": -0.09, "2024-06": 0.31, "2024-09": 0.08, "2024-12": 0.32, "2025-03": -0.9035, "2025-06": 0.15, "2025-09": -0.02, "2025-12": -0.08, "2026-03": -0.49,
Last SUE: -0.04
Qual. Beats: 0
Revenue Revenue of CSTL over the last years for every Quarter: 2021-03: 22.813, 2021-06: 22.758, 2021-09: 23.475, 2021-12: 25.039, 2022-03: 26.852, 2022-06: 34.838, 2022-09: 37.011, 2022-12: 38.338, 2023-03: 42.037, 2023-06: 50.138, 2023-09: 61.493, 2023-12: 66.12, 2024-03: 72.974, 2024-06: 87.002, 2024-09: 85.782, 2024-12: 86.311, 2025-03: 87.988, 2025-06: 86.188, 2025-09: 83.043, 2025-12: 87.01, 2026-03: 83.679,
Rev. CAGR: 29.36%
Rev. Trend: 90.0%
Last SUE: 0.74
Qual. Beats: 0

Warnings

High Debt/EBITDA (41.4) with thin interest coverage (-106.1)

Interest Coverage Ratio -106.1 is critical

Altman Z'' -1.25 < 1.0 - financial distress zone

Tailwinds

No distinct edge detected

Description: CSTL Castle Biosciences

Castle Biosciences, Inc. (CSTL) is a molecular diagnostics provider specializing in gene expression profile (GEP) testing and spatialomics. The company develops and commercializes diagnostic and prognostic solutions for dermatologic cancers, uveal melanoma, Barrett’s esophagus, and atopic dermatitis. Its primary product suite, including DecisionDx-Melanoma and TissueCypher, focuses on risk stratification to guide clinical decision-making and systemic treatment selection.

The company operates within the precision medicine sector, where business models rely heavily on Medicare reimbursement approvals and inclusion in clinical practice guidelines to drive physician adoption. Castle Biosciences targets high-growth markets in dermatology and gastroenterology, utilizing non-invasive genomic testing to reduce unnecessary surgical procedures and improve patient outcomes. For a deeper look into the companys valuation metrics, you may want to consult ValueRay.

Headlines to Watch Out For
  • Medicare reimbursement coverage decisions for DecisionDx-SCC impact core revenue stability
  • TissueCypher adoption rates in gastroenterology markets drive long-term top-line growth
  • Expansion into atopic dermatitis testing diversifies the diagnostic product portfolio
  • Operating margin improvement depends on scaling laboratory efficiencies and sales force productivity
  • Clinical evidence updates for gene expression profile tests influence physician adoption rates
Piotroski VR-10 (Strict) 2.0
Net Income: -12.8m TTM > 0 and > 6% of Revenue
FCF/TA: 0.01 > 0.02 and ΔFCF/TA -7.50 > 1.0
NWC/Revenue: 82.41% < 20% (prev 89.92%; Δ -7.51% < -1%)
CFO/TA 0.09 > 3% & CFO 48.3m > Net Income -12.8m
Net Debt/EBITDA: error (EBITDA <= 0)
Current Ratio: 6.75 > 1.5 & < 3
Outstanding Shares: last quarter (29.9m) vs 12m ago 4.47% < -2%
Gross Margin: 77.07% > 18% (prev 0.82%; Δ 7.62k% > 0.5%)
Asset Turnover: 64.78% > 50% (prev 69.18%; Δ -4.40% > 0%)
Interest Coverage Ratio: -106.1 > 6 (EBITDA TTM -4.79m / Interest Expense TTM 203k)
Altman Z'' -1.25
A: 0.51 (Total Current Assets 328.9m - Total Current Liabilities 48.8m) / Total Assets 547.8m
B: -0.44 (Retained Earnings -238.8m / Total Assets 547.8m)
C: -0.04 (EBIT TTM -21.5m / Avg Total Assets 524.8m)
D: -2.76 (Book Value of Equity -238.8m / Total Liabilities 86.4m)
Altman-Z'' = -1.25 = CCC
Beneish M -3.23
DSRI: 0.77 (Receivables 42.3m/56.4m, Revenue 339.9m/347.1m)
GMI: 1.06 (GM 77.07% / 81.94%)
AQI: 1.11 (AQ_t 0.19 / AQ_t-1 0.17)
SGI: 0.98 (Revenue 339.9m / 347.1m)
TATA: -0.11 (NI -12.8m - CFO 48.3m) / TA 547.8m)
Beneish M = -3.23 (Cap -4..+1) = AA
What is the price of CSTL shares?

As of May 27, 2026, the stock is trading at USD 19.69 with a total of 377,785 shares traded.
Over the past week, the price has changed by +1.92%, over one month by -21.18%, over three months by -38.24% and over the past year by +24.62%.

Is CSTL a buy, sell or hold?

Castle Biosciences has received a consensus analysts rating of 4.89. Therefore, it is recommended to buy CSTL.

  • StrongBuy: 8
  • Buy: 1
  • Hold: 0
  • Sell: 0
  • StrongSell: 0

What are the forecasts/targets for the CSTL price?
Analysts Target Price 45.9 133%
Castle Biosciences (CSTL) - Fundamental Data Overview as of 22 May 2026
Market Cap USD = 607.5m (607.5m USD * 1.0 USD.USD)
P/S = 1.7872
P/B = 1.3166
Revenue TTM = 339.9m USD
EBIT TTM = -21.5m USD
EBITDA TTM = -4.79m USD
Long Term Debt = 8.40m USD (from longTermDebt, last quarter)
Short Term Debt = 2.92m USD (from shortTermDebt, last quarter)
Debt = 63.4m USD (from shortLongTermDebtTotal, last quarter) + Leases 26.7m
Net Debt = -198.3m USD (calculated: Debt 63.4m - CCE 261.7m)
Enterprise Value = 409.2m USD (607.5m + Debt 63.4m - CCE 261.7m)
Interest Coverage Ratio = -106.1 (Ebit TTM -21.5m / Interest Expense TTM 203k)
EV/FCF = 90.57x (Enterprise Value 409.2m / FCF TTM 4.52m)
FCF Yield = 1.10% (FCF TTM 4.52m / Enterprise Value 409.2m)
FCF Margin = 1.33% (FCF TTM 4.52m / Revenue TTM 339.9m)
Net Margin = -3.78% (Net Income TTM -12.8m / Revenue TTM 339.9m)
Gross Margin = 77.07% ((Revenue TTM 339.9m - Cost of Revenue TTM 77.9m) / Revenue TTM)
Gross Margin QoQ = 72.15% (prev 78.95%)
Tobins Q-Ratio = 0.75 (Enterprise Value 409.2m / Total Assets 547.8m)
Interest Expense / Debt = 0.32% (Interest Expense 203k / Debt 63.4m)
Taxrate = 21.0% (US default 21%)
NOPAT = -17.0m (EBIT -21.5m * (1 - 21.00%)) [loss with tax shield]
Current Ratio = 6.75 (Total Current Assets 328.9m / Total Current Liabilities 48.8m)
Debt / Equity = 0.14 (Debt 63.4m / totalStockholderEquity, last quarter 461.4m)
 Debt / EBITDA = 41.41 (negative EBITDA) (Net Debt -198.3m / EBITDA -4.79m)
 Debt / FCF = -43.89 (Net Debt -198.3m / FCF TTM 4.52m)
Total Stockholder Equity = 463.7m (last 4 quarters mean from totalStockholderEquity)
RoA = -2.45% (Net Income -12.8m / Total Assets 547.8m)
RoE = -1.83% (Net Income TTM -12.8m / Total Stockholder Equity 702.5m)
RoCE = -3.03% (EBIT -21.5m / Capital Employed (Equity 702.5m + L.T.Debt 8.40m))
 RoIC = -3.39% (negative operating profit) (NOPAT -17.0m / Invested Capital 502.0m)
 WACC = 5.54% (E(607.5m)/V(670.9m) * Re(6.09%) + D(63.4m)/V(670.9m) * Rd(0.32%) * (1-Tc(0.21)))
Discount Rate = 6.09% (= CAPM, Blume Beta Adj.)
Shares (quarterly) Correlation: 51.11 | Cagr: 4.38%
[DCF] Terminal Value 73.10% ; FCFF base≈19.4m ; Y1≈17.0m ; Y5≈13.8m
[DCF] Fair Price = 13.82 (EV 220.8m - Net Debt -198.3m = Equity 419.1m / Shares 30.3m; r=8.35% [WACC [floored]]; 5y FCF grow -15.0% → 2.50% )
EPS Correlation: N/A | EPS CAGR: N/A | SUE: -0.04 | # QB: 0
Revenue Correlation: 90.01 | Revenue CAGR: 29.36% | SUE: 0.74 | # QB: 0
EPS current Quarter (2026-06-30): EPS=-0.40 | Chg30d=-29.38% | Revisions=-33% | Analysts=8
EPS next Quarter (2026-09-30): EPS=-0.28 | Chg30d=-46.37% | Revisions=-33% | Analysts=8
EPS current Year (2026-12-31): EPS=-1.36 | Chg30d=-15.64% | Revisions=-17% | GrowthEPS=-63.7% | GrowthRev=+1.3%
EPS next Year (2027-12-31): EPS=-0.90 | Chg30d=-65.74% | Revisions=-33% | GrowthEPS=+33.7% | GrowthRev=+12.0%
[Analyst] Revisions Ratio: -33%