CSTL Stock Analysis: Castle Biosciences | NASDAQ

Diagnostics & Research | NASDAQ, USA | Market Cap: 1.045m USD | 12M Return: 62.7% | US14843C1053 | Charts, Fundamentals & Technical Analysis

Diagnostics, Oncology, Dermatology, Gastroenterology
Total Rating 55
Safety 93
Buy Signal 0.29
Diagnostics & Research
Industry Rotation: +7.8
Market Cap: 1.04B
Avg Turnover: 13.5M
Risk 3d forecast
Volatility57.8%
VaR 5th Pctl9.16%
VaR vs Median-3.52%
Reward TTM
Sharpe Ratio1.04
Rel. Str. IBD88.5
Rel. Str. Peer Group58.8
Character TTM
Beta0.617
Beta Downside0.422
Hurst Exponent0.453
Drawdowns 3y
Max DD57.83%
CAGR/Max DD0.37
CAGR/Mean DD0.91
EPS (Earnings per Share) EPS (Earnings per Share) of CSTL over the last years for every Quarter: "2021-06": -0.35, "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": -0.9, "2025-06": 0.15, "2025-09": -0.02, "2025-12": -0.08, "2026-03": -0.49, "2026-06": -0.07,
Last SUE: 0.79
Qual. Beats: 0
Revenue Revenue of CSTL over the last years for every Quarter: 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, 2026-06: 103.546,
Rev. CAGR: 22.00%
Rev. Trend: 87.0%
Last SUE: 3.29
Qual. Beats: 1

Warnings

High Debt/EBITDA With Thin Interest Coverage
High Debt While Negative Cash Flow
Interest Coverage Ratio Critical

Tailwinds

Supp Ema20

Seasonality 7 years of data

Jan +3.3% 37
Feb -15.6% 24
Mar -5.8% 17
Apr -0.6% 0
May -6.6% 18
Jun +6.8% 0
Jul +3.1% 12
Aug +14.4% 61
Sep -10.3% 27
Oct -3.0% 16
Nov -3.9% 15
Dec +2.1% 17

How good or bad each month usually is (without trend). The score below shows how much you can trust it: 0 = pure chance, >40 gets interesting and >55 is strong.

Description: CSTL Castle Biosciences

Castle Biosciences is a molecular diagnostics company that develops and commercializes gene expression profile (GEP) tests and related tissue-based assays. Its flagship DecisionDx-Melanoma test predicts the risk of sentinel lymph node positivity and metastasis in invasive cutaneous melanoma, while DecisionDx-SCC addresses risk stratification in cutaneous squamous cell carcinoma. The company has expanded into adjacent indications with TissueCypher for Barretts esophagus, AdvanceAD-Tx for atopic dermatitis, and DecisionDx-UM for uveal melanoma, selling primarily to dermatology and gastroenterology practices. Founded in 2007 and headquartered in Friendswood, Texas, Castle Biosciences went public on Nasdaq in 2019.

As a clinical GEP-based diagnostics business, the company operates in the dermatology and gastroenterology markets, generating revenue primarily through per-test reimbursement from commercial and Medicare payers. Because the tests are physician-ordered and patient-specific, the business model relies on clinical adoption, inclusion in treatment guidelines, and favorable coverage decisions to drive recurring test volume.

Headlines to Watch Out For
  • DecisionDx-Melanoma test volume growth drives dermatology segment revenue
  • TissueCypher Barretts esophagus adoption accelerates gastroenterology sales
  • NCCN guideline inclusion expands reimbursement coverage and physician adoption
Piotroski VR-10 (Strict) 1.5
Net Income: -19.4m TTM > 0 and > 6% of Revenue
FCF/TA: -0.00 > 0.02 and ΔFCF/TA -6.43 > 1.0
NWC/Revenue: 79.66% < 20% (prev 86.00%; Δ -6.34% < -1%)
CFO/TA 0.08 > 3% & CFO 42.6m > Net Income -19.4m
Net Debt/EBITDA: error (EBITDA <= 0)
Current Ratio: 6.04 > 1.5 & < 3
Outstanding Shares: last quarter (30.4m) vs 12m ago 2.89% < -2%
Gross Margin: 77.26% > 18% (prev 81.00%; Δ -3.74% > 0.5%)
Asset Turnover: 64.61% > 50% (prev 63.57%; Δ 1.05% > 0%)
Interest Coverage Ratio: -50.21 > 6 (EBIT TTM -18.8m / Interest Expense TTM 375k)
Altman Z'' 7.11
A: 0.51 (Total Current Assets 341.1m - Total Current Liabilities 56.5m) / Total Assets 561.2m
B: -0.43 (Retained Earnings -240.9m / Total Assets 561.2m)
C: -0.03 (EBIT TTM -18.8m / Avg Total Assets 553.0m)
D: 5.16 (Book Value of Equity 470.0m / Total Liabilities 91.1m)
Altman-Z'' = 7.11 = AAA
Beneish M -3.10
DSRI: 0.90 (Receivables 48.3m/52.3m, Revenue 357.3m/346.3m)
GMI: 1.05 (GM 81.00% / 77.26%)
AQI: 0.92 (AQ_t 0.18 / AQ_t-1 0.20)
SGI: 1.03 (Revenue 357.3m / 346.3m)
TATA: -0.11 (NI -19.4m - CFO 42.6m) / TA 561.2m)
Beneish M = -3.10 (Cap -4..+1) = AA
What is the price of CSTL shares?

As of August 25, 2026, the stock is trading at USD 33.47 with a total of 356,865 shares traded. Over the past week, the price has changed by +11.75%, over one month by +35.59%, over three months by +69.98% and over the past year by +62.71%.

Current recommended Stop Loss: 30.60 (which is 8.6% or 1.7 ATR below the current price).

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 44 31.5%
Castle Biosciences (CSTL) - Fundamental Data Overview as of 24 August 2026
Market Cap USD = 1.04b (1.04b USD * 1.0 USD.USD)
P/S = 2.9243
P/B = 2.2261
Revenue TTM = 357.3m USD
EBIT TTM = -18.8m USD
EBITDA TTM = -3.24m USD
Long Term Debt = 7.16m USD (from longTermDebt, last quarter)
Short Term Debt = 4.33m USD (from shortTermDebt, last quarter)
Debt = 63.2m USD (from shortLongTermDebtTotal, last quarter) + Leases 26.6m
Net Debt = -203.6m USD (calculated: Debt 63.2m - CCE 266.8m)
Enterprise Value = 841.2m USD (1.04b + Debt 63.2m - CCE 266.8m)
Interest Coverage Ratio = -50.21 (Ebit TTM -18.8m / Interest Expense TTM 375k)
EV/FCF = -1000.0x (Enterprise Value 841.2m / FCF TTM -489k)
FCF Yield = -0.06% (FCF TTM -489k / Enterprise Value 841.2m)
FCF Margin = -0.14% (FCF TTM -489k / Revenue TTM 357.3m)
Net Margin = -5.43% (Net Income TTM -19.4m / Revenue TTM 357.3m)
Gross Margin = 77.26% ((Revenue TTM 357.3m - Cost of Revenue TTM 81.3m) / Revenue TTM)
Gross Margin QoQ = 77.11% (prev 75.46%)
Tobins Q-Ratio = 1.50 (Enterprise Value 841.2m / Total Assets 561.2m)
Interest Expense / Debt = 0.59% (Interest Expense 375k / Debt 63.2m)
Taxrate = 21.0% (US federal default 21%)
NOPAT = -14.9m (EBIT -18.8m * (1 - 21.00%)) [loss with tax shield]
Current Ratio = 6.04 (Total Current Assets 341.1m / Total Current Liabilities 56.5m)
Debt / Equity = 0.13 (Debt 63.2m / totalStockholderEquity, last quarter 470.0m)
 Debt / EBITDA = 62.91 (negative EBITDA) (Net Debt -203.6m / EBITDA -3.24m)
 Debt / FCF = 416.3 (negative FCF - burning cash) (Net Debt -203.6m / FCF TTM -489k)
 Total Stockholder Equity = 467.3m (last 4 quarters mean from totalStockholderEquity)
RoA = -3.51% (Net Income -19.4m / Total Assets 561.2m)
RoE = -4.15% (Net Income TTM -19.4m / Total Stockholder Equity 467.3m)
RoCE = -3.97% (EBIT -18.8m / Capital Employed (Equity 467.3m + L.T.Debt 7.16m))
 RoIC = -3.03% (negative operating profit) (NOPAT -14.9m / Invested Capital 491.1m)
 WACC = 7.71% (E(1.04b)/V(1.11b) * Re(8.15%) + D(63.2m)/V(1.11b) * Rd(0.59%) * (1-Tc(0.21)))
Discount Rate = 8.15% (= CAPM, Blume Beta Adj.)
Shares (quarterly) Correlation: 67.68 | Cagr: 4.58%
 [DCF] Fair Price = unknown (Cash Flow -489k)
 EPS Correlation: N/A | EPS CAGR: N/A | SUE: 0.79 | # QB: 0
Revenue Correlation: 87.02 | Revenue CAGR: 22.00% | SUE: 3.29 | # QB: 1
EPS current Quarter (2026-09-30): EPS=-0.36 | Chg30d=-20.59% | Revisions=-55% | Analysts=9
EPS current Year (2026-12-31): EPS=-1.27 | Chg30d=+9.41% | Revisions=+36% | GrowthEPS=-53.3% | GrowthRev=+8.3%
EPS next Year (2027-12-31): EPS=-0.99 | Chg30d=-5.96% | Revisions=+0% | GrowthEPS=+22.3% | GrowthRev=+9.8%
[Analyst] Revisions Ratio: -7% (up=11, down=13)