CSTL
Castle Biosciences, Inc. Common Stock
stockNASDAQ
Market OpenOct 5, 2026 10:17:58 AM EDT
35.82USD+0.731%(+0.26)6,990
30.10Bid36.26Ask6.16SpreadAs of 2026-09-15, there were 1,899,369 shares short with a short interest of 7.04%.
CSTL Short Interest - Official
Short Interest
CSTL Short Position Change - Official
Short Position Change
CSTL Short Interest - Official
| Settlement Date1 | Short Interest % | Short Position | Days to Cover2 | Short Position Change | Short Position Change % | Shares Out | Shares Float |
|---|---|---|---|---|---|---|---|
| 2026-09-15 | 7.04 | 1,899,369 | 7.36 | -77,385 | -3.91 | 30,549,507 | 26,991,406 |
| 2026-08-31 | 7.32 | 1,976,754 | 5.05 | +223,149 | +12.73 | 30,549,507 | 26,991,406 |
| 2026-08-14 | 6.50 | 1,753,605 | 3.68 | +191,617 | +12.27 | 30,549,507 | 26,991,406 |
| 2026-07-31 | 5.79 | 1,561,988 | 3.17 | +140,195 | +9.86 | 30,549,507 | 26,991,406 |
| 2026-07-15 | 5.31 | 1,421,793 | 5.66 | -69,957 | -4.69 | 30,329,952 | 26,790,143 |
| 2026-06-30 | 5.57 | 1,491,750 | 3.18 | +6,689 | +0.45 | 30,329,952 | 26,778,011 |
| 2026-06-15 | 5.55 | 1,485,061 | 5.23 | +69,316 | +4.90 | 30,329,952 | 26,765,879 |
| 2026-05-15 | 5.49 | 1,415,745 | 2.23 | -13,271 | -0.93 | 30,329,952 | 25,775,606 |
| 2026-04-30 | 5.30 | 1,429,016 | 4.73 | -34,031 | -2.33 | 30,295,965 | 26,975,575 |
| 2026-04-15 | 5.42 | 1,463,047 | 5.26 | -71,353 | -4.65 | 30,295,965 | 26,975,575 |
| 2026-03-31 | 5.69 | 1,534,400 | 4.87 | +105,389 | +7.37 | 29,731,198 | 26,975,575 |
| 2026-03-13 | 5.30 | 1,429,011 | 3.50 | +34,717 | +2.49 | 29,731,198 | 26,975,575 |
| 2026-02-27 | 5.17 | 1,394,294 | 2.89 | +35,244 | +2.59 | 29,188,659 | 26,975,575 |
| 2026-02-13 | 5.04 | 1,359,050 | 3.09 | -155,845 | -10.29 | 29,188,659 | 26,975,575 |
| 2026-01-30 | 5.62 | 1,514,895 | 4.07 | -18,063 | -1.18 | 29,188,659 | 26,975,575 |
| 2026-01-15 | 5.68 | 1,532,958 | 4.03 | +25,282 | +1.68 | 29,188,659 | 26,975,575 |
| 2025-12-31 | 5.59 | 1,507,676 | 5.28 | -214,790 | -12.47 | 29,188,659 | 26,975,575 |
| 2025-12-15 | 6.40 | 1,722,466 | 3.96 | -112,882 | -6.15 | 29,188,659 | 26,910,192 |
| 2025-11-28 | 6.81 | 1,835,348 | 3.73 | +193,654 | +11.80 | 29,188,659 | 26,965,943 |
| 2025-11-14 | 6.09 | 1,641,694 | 2.44 | +94,444 | +6.10 | 29,188,659 | 26,964,483 |
| 2025-10-31 | 5.78 | 1,547,250 | 6.42 | -60,819 | -3.78 | 29,008,281 | 26,762,170 |
| 2025-10-15 | 6.01 | 1,608,069 | 5.46 | +53,359 | +3.43 | 29,008,281 | 26,761,009 |
Historical data is split-adjusted.
1 Data from Finra. Finra publishes an updated file every two weeks.
2 Days to Cover (DTC) is also called Short Ratio. This is the Short Position / Average Daily Trading Volume.