CASTLE BIOSCIENCES INC (CSTL)

NASDAQ · Healthcare Services · Services-Medical Laboratories

Price: $34.88
Day: +0.09%
Market cap: $1.07B

Close 2026-09-23.

The company

Overview Castle Biosciences is a molecular diagnostics company offering innovative test solutions to aid clinicians in the diagnosis and treatment of dermatologic cancers, Barrett’s esophagus (“BE”), atopic dermatitis (“AD”), uveal melanoma (“UM”). Since our inception in 2008, it has been our vision to transform disease management by keeping people first: patients, clinicians, employees and investors. This foundational strategy remains the guidepost for the direction of our company and the basis of long-term value creation.

From Item 1: Overview.

By product & service

Dermatologic — 63%
Non Dermatologic — 37%

Institutional holders

Largest positions reported on Form 13F for the quarter ended 2026-06-30, by value.

RTW INVESTMENTS, LP — $66.26M
PRINCIPAL FINANCIAL GROUP INC — $41.17M
BlackRock, Inc. — $38.23M
VANGUARD CAPITAL MANAGEMENT LLC — $29.25M
BlackRock, Inc. — $23.74M
VANGUARD PORTFOLIO MANAGEMENT LLC — $20.05M
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC — $19.67M
STATE STREET CORP — $19.63M

Insider trades

Open-market buys and sales filed on Form 4, newest first. Grants, option exercises and tax withholding are left out.

Juvenal Tobin W (Chief Commercial Officer) sold 3,294 shares at $35.14 on 2026-09-15
Juvenal Tobin W (Chief Commercial Officer) sold 3,306 shares at $32.32 on 2026-09-14
MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 8,361 shares at $32.00 on 2026-09-11
MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 3,124 shares at $32.00 on 2026-09-11
MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 2,656 shares at $32.00 on 2026-09-11
MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 223 shares at $32.78 on 2026-09-11

Recent filings

4 — 2026-09-16
4 — 2026-09-15
144 — 2026-09-14
144 — 2026-09-11
4 — 2026-09-03
4 — 2026-09-02
4 — 2026-09-01
4 — 2026-08-27
4 — 2026-08-26
144 — 2026-08-25