Question 1

Who are the insiders buying CASTLE BIOSCIENCES INC stock?

Accepted Answer

InsiderAct tracks all open-market purchases of CASTLE BIOSCIENCES INC stock by corporate insiders — including officers, directors, and shareholders owning more than 10% — sourced from public SEC Form 4 filings.

Question 2

What does insider buying at a company mean?

Accepted Answer

When a corporate officer, director, or major shareholder purchases their own company's stock on the open market using personal funds, it signals confidence in the company's outlook. This is especially meaningful when multiple insiders buy within the same 7–14 day window (cluster buying) or when the purchase size exceeds $100,000.

Question 3

How do I find cluster buying signals for a company?

Accepted Answer

InsiderAct automatically detects cluster buying — two or more insiders independently purchasing shares within a 14-day window. When a cluster buy signal is active for a company, it appears prominently on the company's InsiderAct page and on the Signals tab.

Question 4

Has CASTLE BIOSCIENCES INC had any recent large insider purchases?

Accepted Answer

InsiderAct tracks all open-market purchases of $100,000 or more at CASTLE BIOSCIENCES INC. Large insider purchases are flagged as high-conviction signals because they represent meaningful personal capital commitments by executives or directors who have direct visibility into the company's operations and prospects.

Question 5

Where do the insider transactions on this page come from?

Accepted Answer

All transactions shown on InsiderAct company pages are sourced directly from SEC EDGAR Form 4 filings — the mandatory public disclosures that corporate insiders must submit within 2 business days of any stock transaction. InsiderAct ingests these filings in near real time and filters for open-market purchases and sales.


2026-09-02	2026-08-31	Juvenal Tobin W	CCO	Sale	1,730	$32.81	$56,761
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Exercise Conversion	12,428	$2.39	$29,703
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	11,472	$33.14	$380,182
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	2,505	$33.14	$83,016
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	2,129	$33.14	$70,555
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	956	$33.88	$32,389
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	257	$33.14	$8,517
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	209	$33.88	$7,081
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	177	$33.88	$5,997
2026-09-01	2026-08-28	Maetzold Derek J	CEO	Sale	21	$33.88	$711

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