Castle Biosciences, Inc. (CSTL) Stock

About Castle Biosciences, Inc.

Castle Biosciences, Inc. is led by CEO Derek J. Maetzold, employs 784 people, headquartered in US, publicly traded since 2019.

Castle Biosciences, Inc. (CSTL) stock trades at $33.08 with a market capitalization of $1.01B. The stock is valued at a negative price-to-earnings (P/E) ratio of -53.92, reflecting a net loss over the last twelve months, price-to-book of 2.30, price-to-sales of 3.04. Over the past 52 weeks the stock has ranged between $17.72 and $44.28, and currently trades 25.3% below its 52-week high.

On profitability, Castle Biosciences, Inc. generates a return on equity (ROE) of -4.15% (negative, reflecting a net loss), return on capital employed of -6.36%, an operating margin of -12.50%, a net profit margin of -5.43%.

Castle Biosciences, Inc. by the numbers, 2017–2025

Between 2017 and 2025 Castle Biosciences, Inc. reported revenue of $14.0M rising to $344.0M, a change of +2357.1% across 9 years. Compounded, revenue has grown 40.4% a year over five years, 35.9% over three, 3.6% over the last twelve months. Net profit fell to $-24.0M.

Operating margin went from -79.3% in 2017 to -12.4% in 2025, a gain of 66.8 percentage points. The most recent net margin is -5.43%. On a trailing twelve-month basis to Jun '26, revenue is $358.0M and net profit $-20.0M.

Borrowings rose from $19.0M to $37.0M, cash from operations was $64.0M in the latest year, positive in 4 of the last 9.

Return on equity has averaged -8.0% over five years, and was -5.1% in the most recent year.

The share price itself has compounded at —% a year over five years, —% over three, —% over the last year. Past price movement is history, not a forecast.

Figures are as reported and in the company's own reporting currency. They describe what has already happened and carry no implication about what follows.

Castle Biosciences, Inc. (CSTL) — frequently asked questions