James A. Brock - 17 Feb 2026 Form 4/A - Amendment Insider Report for Core Natural Resources, Inc. (CNR)

Role: Executive Chair and CEO, Director
Signature: /s/ Rosemary L. Klein, Attorney-in-Fact for James A. Brock
Issuer symbol: CNR
Transactions as of: 17 Feb 2026
Net transactions value: -$263,322
Form type: 4/A - Amendment
Filing time: 23 Feb 2026, 16:11:10 UTC
Date Of Original Report: 19 Feb 2026
Previous filing: 14 Nov 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Brock James A	Executive Chair and CEO, Director	275 TECHNOLOGY DRIVE, SUITE 101, CANONSBURG	/s/ Rosemary L. Klein, Attorney-in-Fact for James A. Brock	23 Feb 2026	0001620612

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CNR	Common stock, par value $0.01 per share	Tax liability	$263,322	-2,960	-1.1%	$88.96	271,415	18 Feb 2026	Direct	F1
holding	CNR	Common stock, par value $0.01 per share						266,975	17 Feb 2026	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	On February 19, 2026, the reporting person filed a Form 4 (the "Original Form 4") which inadvertently reported in the second row of Table I an incorrect amount of shares of common stock withheld to satisfy the reporting person's tax liability due to a clerical error. The corrected amount of securities withheld to satisfy the reporting person's tax liability was 2,960 shares.
F2	Due to immaterial clerical rounding errors, the reporting person's Original Form 4 inadvertently reported an incorrect total amount of securities directly beneficially owned by the reporting person and mistakenly indicated an incorrect amount of unvested restricted stock units owned. The corrected amount of securities beneficially owned by the reporting person is 266,975, of which 44,640 shares represent unvested restricted stock units.

Content

On February 19, 2026, the reporting person filed a Form 4 (the "Original Form 4") which inadvertently reported in the second row of Table I an incorrect amount of shares of common stock withheld to satisfy the reporting person's tax liability due to a clerical error. The corrected amount of securities withheld to satisfy the reporting person's tax liability was 2,960 shares.

Due to immaterial clerical rounding errors, the reporting person's Original Form 4 inadvertently reported an incorrect total amount of securities directly beneficially owned by the reporting person and mistakenly indicated an incorrect amount of unvested restricted stock units owned. The corrected amount of securities beneficially owned by the reporting person is 266,975, of which 44,640 shares represent unvested restricted stock units.