X0508 4 2025-08-18 0000906553 BOYD GAMING CORP BYD 0001186742 JOHNSON MARIANNE BOYD 6465 S. RAINBOW BLVD. LAS VEGAS NV 89118 1 1 1 0 Executive Chairman 0 Common Stock 39088 D Common Stock 2025-08-18 4 J 0 909091 0.00 D 1487858 I By Limited Partnership* Common Stock 2025-08-18 4 J 0 300000 0.00 A 1804379 I By Trust* Common Stock 4800000 I By Limited Liability Company* Common Stock 25555 I By Trust* Common Stock 90964 I By Trust* Common Stock 1100000 I By Limited Liability Company* Common Stock 4004000 I By Limited Liability Company* Transaction reflects the distribution of an aggregate of 909,091 shares of common stock by BG-00 Limited Partnership to the Marianne Boyd Johnson Gaming Properties Trust and three additional beneficiaries. By BG-00 Limited Partnership, of which the Marianne Boyd Gaming Properties Trust, of which the reporting person is the trustee, settlor and beneficiary, is the general partner thereof. Transaction reflects the receipt of 300,000 shares of common stock in distribution from BG-00 Limited Partnership, as described in footnote (1). By Marianne Boyd Johnson as Trustee of the Marianne Boyd Johnson Gaming Properties Trust. By WSB-BYD, LLC, of which the reporting person is the Manager. By Marianne Boyd Johnson as Trustee of the Justin Boyd Education Trust Dated 11/1/99. By the Johnson Children's Trust Dated 6/24/96, Bruno Mark, Trustee. By BG-SUB, LLC of which Marianne Boyd Johnson is the managing member thereof. By BYD-SST LLC, of which Marianne Boyd Johnson is the managing member thereof. *The reporting person expressly disclaims beneficial ownership of any securities of the Issuer except for those securities that are owned directly by the Reporting Person or to the extent of the Reporting Person's pecuniary interest in a trust or other entity which owns such securities. /s/ Uri Clinton, attorney-in-fact for Marianne Boyd Johnson 2025-08-20