Castle Biosciences
Provides clinician-facing molecular diagnostic tests across dermatology and gastroenterology.
$33.50
After-hours close+0.06 (+0.18%)
At close$33.44(−2.39%)
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Breakdown13F · Form 4
Institutions 93.23%28.48M sharesInsiders 1.51%461.6K sharesOther 5.26%1.61M shares
Shares outstanding 30.55M · Float 26.99M · 88.4% free float
Institutions13F, as of Jun 30, 2026
179 holders · 28.48M shares · 27 new positions · 106 increased · 56 reduced · 34 closed
| Holder | Shares | % outstanding | Chg q/q | Filed |
|---|---|---|---|---|
| BlackRock, Inc. | 3.29M | 10.78% | +309.0K | Aug 7, 2026 |
| RTW Investments, LP | 2.78M | 9.09% | +20.0K | Aug 14, 2026 |
| Principal Financial Group Inc | 1.73M | 5.65% | −43.2K | Aug 4, 2026 |
| Vanguard Capital Management LLC | 1.23M | 4.01% | +49.0K | Aug 13, 2026 |
| Acadian Asset Management LLC | 918.7K | 3.01% | +434.2K | Aug 13, 2026 |
| Vanguard Portfolio Management LLC | 840.8K | 2.75% | −21.0K | Aug 13, 2026 |
| Summit Partners Public Asset Management, LLC | 824.9K | 2.70% | −115.8K | Aug 14, 2026 |
| State Street Corp | 822.1K | 2.69% | +53.0K | Aug 7, 2026 |
Beneficial owners13D/G · 5% or more, as filed
| Holder | % of class | Shares | Form | Filed |
|---|---|---|---|---|
| RTW Investments, LP | 9.30% | 2.76M | 13G | May 15, 2026 ↗ |
| BlackRock, Inc. | 8.20% | 2.34M | 13G | Apr 23, 2025 ↗ |
InsidersForm 4
| Insider | Role | Shares | % outstanding | Filed |
|---|---|---|---|---|
| Kristen M. Oelschlager | officer: Chief Operating Officer | 85.9K | 0.28% | Aug 26, 2026 |
| Tobin W. Juvenal | officer: Chief Commercial Officer | 66.9K | 0.22% | Aug 27, 2026 |
| Ellen Goldberg | director | 40.9K | 0.13% | May 27, 2026 |
| Tiffany Olson | director | 39.6K | 0.13% | May 27, 2026 |
| Kim Caple | director | 36.1K | 0.12% | May 27, 2026 |
| Miles Harrison | director | 35.6K | 0.12% | May 27, 2026 |
| Frank Stokes | officer: Chief Financial Officer | 35.2K | 0.12% | Aug 18, 2026 |
| Derek J. Maetzold | director, officer: Pres. & Chief Exec. Officer | 33.0K | 0.11% | Aug 18, 2026 |
| Rodney Cotton | director | 33.0K | 0.11% | May 27, 2026 |
| G. Bradley Cole | director | 33.0K | 0.11% | May 27, 2026 |
3 ten-percent owners hold 3.41M shares by Form 4, outside the officers-and-directors figure above · 6 people have not refiled in the last 18 months (740.0K shares), so they are not in the figure above
Latest trades
| Date | Insider | Type | Shares | Avg price | Owned after |
|---|---|---|---|---|---|
| Aug 25, 2026 | Tobin W. Juvenalofficer: Chief Commercial Officer | Sale | 9,050 | $35.04 | 66,914 |
| Aug 25, 2026 | Kristen M. Oelschlagerofficer: Chief Operating Officer | Sale · 2 lots | 12,384 | $34.42 | 72,649 |
| Aug 24, 2026 | Kristen M. Oelschlagerofficer: Chief Operating Officer | Sale | 12,218 | $33.69 | 85,033 |
| Aug 17, 2026 | Tobin W. Juvenalofficer: Chief Commercial Officer | Sale | 1,730 | $29.59 | 75,964 |
| Aug 14, 2026 | Derek J. Maetzolddirector, officer: Pres. & Chief Exec. Officer | Sale · 4 lots | 6,398 | $30.02 | 33,013 |
| Aug 14, 2026 | Frank Stokesofficer: Chief Financial Officer | Sale | 24,908 | $29.77 | 35,177 |
| Aug 5, 2026 | Derek J. Maetzolddirector, officer: Pres. & Chief Exec. Officer | Sale · 3 lots | 3,575 | $30.68 | 41,086 |
| Aug 4, 2026 | Derek J. Maetzolddirector, officer: Pres. & Chief Exec. Officer | Sale · 6 lots | 35,441 | $31.11 | 41,559 |
| Nov 24, 2025 | Tobin W. Juvenalofficer: Chief Commercial Officer | Sale | 1,301 | $38.39 | 77,694 |
| Aug 3, 2026 | Kristen M. Oelschlagerofficer: Chief Operating Officer | Sale · 3 lots | 8,586 | $29.77 | 13,288 |
CongressHouse and Senate disclosures
Not reported.