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CSTL - Castle Biosciences Inc

Insider Sale by Maetzold Derek J (Pres, Chief Exec. Officer)

1 Month
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Trade Summary

4 days ago, Maetzold Derek J, serving as Pres, Chief Exec. Officer at Castle Biosciences Inc (CSTL), sold 30,779 shares at $25.75 per share, for a total transaction value of $792,410.00. Following this transaction, Maetzold Derek J now holds 298,515 shares of CSTL.

This sale represents a 9.00% decrease in Maetzold Derek J's stake in the company. This is considered a high-conviction trade given the significant change in ownership.

The trade was executed on Friday, March 13, 2026 and publicly disclosed via SEC Form 4 filing on Tuesday, March 17, 2026, 4 days after the trade was made.

Castle Biosciences Inc operates in the HEALTHCARE sector, specifically within the DIAGNOSTICS & RESEARCH industry. Insider selling activity in this sector can provide valuable signals about industry trends and company-specific developments.

Maetzold Derek J

Pres, Chief Exec. Officer

Derek J. Maetzold is the Founder, President, Chief Executive Officer, and Board Member of Castle Biosciences Inc. (CSTL), a molecular diagnostics company focused on personalized testing for cancers like skin cancer.[[1]](https://convention.bio.org/speaker/derek-maetzold)[[2]](https://txlifescienceforum.org/person/derek-maetzold) He founded the company in 2007, launching operations in late 2008 with co-founders Toby Juvenal and Kristen Oelschlager, driven by the vision to enhance cancer treatment plans through genomic information alongside traditional clinical factors.[[1]](https://convention.bio.org/speaker/derek-maetzold)[[2]](https://txlifescienceforum.org/person/derek-maetzold)[[4]](https://career.egr.uh.edu/partners/industry-advisory-board/maetzold) Under his leadership, Castle Biosciences achieved successful private financing rounds, a 2019 IPO, and acquisitions including the myPath® Melanoma test and Cernostics, Inc. in 2021.[[2]](https://txlifescienceforum.org/person/derek-maetzold) The company, headquartered in Friendswood, Texas, develops diagnostic and prognostic tests for dermatologic cancers and other high-need diseases.[[3]](https://www.zoominfo.com/p/Derek-Maetzold/331878065) Prior to Castle Biosciences—his first venture in molecular diagnostics—Maetzold spent 24 years in pharmaceutical development and commercialization, dividing time between multinational firms Sandoz (now Novartis), Schering (now Merck), and biotech companies Amylin (now BMS/AstraZeneca) and Encysive Pharmaceuticals (now Pfizer), focusing on business development, licensing, and commercial oversight of pre-approved therapies.[[1]](https://convention.bio.org/speaker/derek-maetzold)[[2]](https://txlifescienceforum.org/person/derek-maetzold)[[3]](https://www.zoominfo.com/p/Derek-Maetzold/331878065)[[4]](https://career.egr.uh.edu/partners/industry-advisory-board/maetzold) He holds a Bachelor of Science from George Mason University and has received prestigious awards, including a Gold Lifetime Achievement Award from the 2025 American Business Awards and CEO of the Year from The CEO Magazine.[[3]](https://www.zoominfo.com/p/Derek-Maetzold/331878065)[[5]](https://thedermdigest.com/for-the-win-castle-biosciences-ceo-derek-maetzold-receives-high-honor-from-the-american-business-awards/)[[6]](https://ir.castlebiosciences.com/news/news-details/2025/Castle-Biosciences-Founder-President-and-CEO-Derek-Maetzold-Honored-with-the-CEO-of-the-Year-Award-by-The-CEO-Magazine/default.aspx)

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Trade Price

$25.75

Quantity

30,779

Total Value

$792,410.00

Shares Owned

298,515

Trade Date

Friday, March 13, 2026

4 days ago

SEC Filing Date

Tuesday, March 17, 2026

Filed 4 days after trade

HEALTHCAREDIAGNOSTICS & RESEARCH

About Castle Biosciences Inc

Company Overview

No company information available
View news mentioning CSTL

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