CSTL — CASTLE BIOSCIENCES INC
Price · 2024-08-26 → 2026-08-21
499 daily closes shownAnonymous view is capped at two years of history. A free account extends it to five, and Pro opens the whole archive back to 2019-07-25.
Performance
Technicals
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Measured signals that fired on CSTL
| date | signal | measured base rate |
|---|---|---|
| 2026-08-20 | Fair value gap, bullish structure | -0.67% over 21 days · t = -6.43 · n = 111,973 statistically distinguishable from its control group |
| 2026-08-20 | Equal highs taken out structure | -0.70% over 21 days · t = -8.28 · n = 68,636 statistically distinguishable from its control group |
| 2026-08-18 | Bollinger bandwidth breaks out of its own compression structure | -0.63% over 21 days · t = -2.80 · n = 7,196 statistically distinguishable from its control group |
| 2026-05-07 | Fair value gap, bearish structure | -0.45% over 21 days · t = -3.29 · n = 108,591 statistically distinguishable from its control group |
| 2026-04-01 | Fair value gap, bullish structure | -0.67% over 21 days · t = -6.43 · n = 111,973 statistically distinguishable from its control group |
| 2026-03-30 | Fair value gap, bearish structure | -0.45% over 21 days · t = -3.29 · n = 108,591 statistically distinguishable from its control group |
Excess return against a matched control group, on a point-in-time universe that includes delisted companies. Most families do not survive that. How the measurement works →
Insider transactions (Form 4)
| date | insider | what | shares | price | value |
|---|---|---|---|---|---|
| 2026-08-17 | Juvenal Tobin W Chief Commercial Officer | Open-market sale 10b5-1 plan | 1.7K | 29.59 | 51.2K |
| 2026-08-14 | Stokes Frank Chief Financial Officer | Open-market sale | 24.9K | 29.77 | 741.5K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 2.7K | 30.02 | 81.5K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 2.3K | 30.02 | 69.2K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 1.1K | 30.02 | 33.0K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 278 | 30.02 | 8.3K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 278 | 30.02 | 8.3K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 278 | 30.02 | 8.3K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Open-market sale 10b5-1 plan | 278 | 30.02 | 8.3K |
| 2026-08-14 | MAETZOLD DEREK J Pres. & Chief Exec. Officer | Option exercise 10b5-1 plan | 1.1K | 2.39 | 2.6K |
Open-market purchases (code P) are the informative ones. Grants, option exercises and tax withholding are compensation mechanics, not decisions. How to read a Form 4 →
Largest institutional holders
| manager | value | shares |
|---|---|---|
| BlackRock, Inc. | 73.2M | 3.0M |
| RTW INVESTMENTS, LP | 67.7M | 2.8M |
| PRINCIPAL FINANCIAL GROUP INC | 43.5M | 1.8M |
| Portolan Capital Management, LLC | 33.1M | 1.4M |
| VANGUARD CAPITAL MANAGEMENT LLC | 28.9M | 1.2M |
| DIMENSIONAL FUND ADVISORS LP | 25.5M | 1.0M |
| SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC | 23.1M | 940.7K |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 21.2M | 861.8K |
| Allianz Asset Management GmbH | 19.9M | 811.3K |
| STATE STREET CORP | 18.9M | 769.1K |
13F positions as of 2026-03-31, filed up to 45 days after quarter end. Long-only US equity — shorts and derivatives never appear. What 13F does and does not show →
Short selling
This is off-exchange short volume, not short interest: it is flow, not position, and 40–50% is normal because market makers short to fill your buy. Why that number misleads →
Recent headlines
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