X0609 4 2026-08-19 0001710340 Eton Pharmaceuticals, Inc. ETON 0001669976 BRYNJELSEN SEAN false C/O ETON PHARMACEUTICALS, INC. 21925 W. FIELD PARKWAY, SUITE 235 DEERPARK IL 60010-7208 1 1 President & CEO 0 Common Stock 2026-08-19 4 S 0 8978 62.65 D 1052216 D Common Stock 2026-08-20 4 S 0 47307 60.17 D 1004909 D Common Stock 2026-08-20 4 S 0 36373 61.11 D 968536 D Common Stock 2026-08-20 4 S 0 7342 62.12 D 961194 D The shares were sold in multiple trades at prices ranging from $62.50 to $63.41. The price above reflects the weighted average sales price. The Reporting Person will provide upon request by the Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. The shares were sold in multiple trades at prices ranging from $59.59 to $60.59. The price above reflects the weighted average sales price. The shares were sold in multiple trades at prices ranging from $60.61 to $61.61. The price above reflects the weighted average sales price. The shares were sold in multiple trades at prices ranging from $61.63 to $62.52. The price above reflects the weighted average sales price. /s/ Judith Matthews 2026-08-20