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The price of Castle Biosciences, Inc. (CSTL) on October 9, 2026 is 34.42 USD, +2.11% on the day. Over 52 weeks the stock traded between 17.72 USD and 44.28 USD; the price now sits 63% of the way up that range. Over the past year the price changed by +45.91%. Market capitalization is 1.04 billion USD, rank 13 among 23 stocks of the same industry with a known capitalization.
Closing prices for 9 October 2026
Next earnings report: 2 November 2026 · Earnings calendar
Change over the period shown (line colour): +50.90 %
Castle Biosciences, Inc. trades on Nasdaq under the ticker CSTL. The company belongs to the Health care sector. The trading history on this page starts on 25 July 2019.
Over the past 52 weeks CSTL has traded between 17.72 $ and 44.28 $. As of 9 October 2026 the price stood 62.87 % of the way from the 52-week low to the high.
Over one year CSTL shares rose 45.91 %; over six months they rose 48.81 %. Volatility over 90 days is 50.02 %. Dividends are not included: this is price change only, as of 9 October 2026.
The company reported a loss over the last four quarters, so a price-to-earnings ratio is not calculated. Price to sales is 3.1, below the sector median of 4.0. Price to book is 2.3, below the sector median of 2.5. Calculated from reports for the period ending 31 March 2026.
| Date | Open | High | Low | Close | Volume, shares |
|---|---|---|---|---|---|
| 9 October 2026 | 33.52 | 34.52 | 33.39 | 34.42 | 249,100 |
| 8 October 2026 | 32.54 | 33.76 | 32.25 | 33.71 | 373,800 |
| 7 October 2026 | 33.15 | 33.72 | 32.77 | 33.00 | 351,500 |
| 6 October 2026 | 36.65 | 37.99 |
The series is stated in the current share scale after splits; dividends are not included in the price
Based on the last 12 months of reports, through 31 March 2026
The sector median covers every company in the sector on the US market, loss-making ones included.
Address:1500 W. PARKWOOD AVE. SUITE 400, FRIENDSWOOD, TX, 77546, US
Castle Biosciences, Inc. reported revenue of 340M $ and a net loss of 13M $ over the last four quarters. Net margin is −3.78 %. Revenue changed by −2.06 % year over year. Earnings per share are −0.42 $. Market capitalisation is 1.0B $.
CSTL has a return on equity of −2.78 %, above the sector median of −41.68 %. Return on assets is −2.34 %, above the sector median of −32.11 %. Operating margin is −9.79 %, above the sector median of −26.84 %.
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| 33.10 |
| 33.36 |
| 609,100 |
| 5 October 2026 | 35.45 | 36.76 | 35.10 | 36.65 | 377,200 |
| 2 October 2026 | 35.56 | 35.92 | 34.75 | 35.56 | 167,700 |
| 1 October 2026 | 36.10 | 36.99 | 35.17 | 35.26 | 522,300 |
| 30 September 2026 | 34.90 | 36.03 | 34.14 | 35.53 | 639,600 |
| 29 September 2026 | 35.72 | 36.24 | 34.24 | 34.88 | 318,600 |
| 28 September 2026 | 35.81 | 36.27 | 35.09 | 35.93 | 228,400 |
| 25 September 2026 | 35.19 | 36.12 | 34.44 | 35.81 | 437,700 |
| 24 September 2026 | 34.88 | 35.84 | 33.90 | 35.19 | 439,200 |
| 23 September 2026 | 34.74 | 34.97 | 33.99 | 34.88 | 348,300 |
| 22 September 2026 | 35.53 | 35.53 | 34.57 | 34.85 | 431,000 |
| 21 September 2026 | 35.68 | 35.68 | 34.48 | 34.99 | 391,700 |
| 18 September 2026 | 36.54 | 36.54 | 35.29 | 35.34 | 530,200 |
| 17 September 2026 | 35.98 | 36.85 | 34.94 | 36.78 | 364,600 |
| 16 September 2026 | 35.50 | 36.82 | 35.26 | 35.48 | 559,300 |
| 15 September 2026 | 33.64 | 35.69 | 33.64 | 35.50 | 519,800 |
| 14 September 2026 | 32.30 | 33.53 | 32.16 | 33.44 | 165,400 |