MARK A. ALEXANDER - 01 Mar 2026 Form 4 Insider Report for Builders FirstSource, Inc. (BLDR)

Role: Director
Signature: /s/ Minator Azemi, by power of attorney
Issuer symbol: BLDR
Transactions as of: 01 Mar 2026
Net transactions value: +$31,183
Form type: 4
Filing time: 03 Mar 2026, 16:05:25 UTC
Previous filing: 03 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
ALEXANDER MARK A	Director	C/O BUILDERS FIRSTSOURCE, INC., 6031 CONNECTION DR., STE. 400, IRVING	/s/ Minator Azemi, by power of attorney	03 Mar 2026	0001212607

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	BLDR	Common Stock, par value $0.01 per share	Award	$31,183	+299	+0.67%	$104.29	44,946	01 Mar 2026	Direct	F1

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

Explanation of Responses:

Id	Content
F1	Reflects acquisition of shares in lieu of cash compensation for services as a director under the Corporation's 2014 Incentive Plan pursuant to the Corporation's Amended and Restated Director Compensation Policy.