Form 4 for CSTL CASTLE BIOSCIENCES INC

Accepted 2026-07-06 16:24:56 ET · period of report 2026-07-01 · accession 0001628280-26-047286 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X	Filed	Traded	Ticker	Insider	Title	Type	Price	Qty	Owned	ΔOwn	Value
MT	2026-07-06 16:24	2026-07-01	CSTL	Oelschlager Kristen M	COO	S - Sale	$24.42	-8,586	21.9K	-28%	-$209.7K

Purchase Sale Sale after option exercise All abbreviations

#	Table	Security	Date	Code	A/D	Shares	Price	Owned after	Own	Exercise / expiry	Underlying	Footnotes
1	Common	Common Stock	2026-07-01	S	D	8,186	$24.40	22,274	D	—	—	(F1) These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person, on March 17, 2026. (F2) This transaction was executed in multiple trades at prices ranging from $23.73 to $24.72, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
2	Common	Common Stock	2026-07-01	S	D	400	$24.78	21,874	D	—	—	(F1) These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person, on March 17, 2026. (F3) This transaction was executed in multiple trades at prices ranging from $24.77 to $24.79, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.