X0609 4 2026-07-31 0001710340 Eton Pharmaceuticals, Inc. ETON 0001968254 Krempa David false C/O ETON PHARMACEUTICALS, INC. 21925 W. FIELD PARKWAY, SUITE 235 DEERPARK IL 60010-7208 1 Chief Business Officer 0 Common Stock 2026-07-31 4 A 0 128985 0 A Common Stock 128985 128985 D On July 31, 2026, the reporting person was granted 128,985 performance-vested restricted stock units granted under the Issuer's 2018 equity incentive plan. Each restricted stock unit represents the right to acquire one share of Issuer common stock. The award vests in full, and all restrictions lapse, immediately upon the closing price of the Issuer's common stock equaling or exceeding $72.36 per share for one trading day at any time prior to the third anniversary of the grant date. If this market condition is not satisfied prior to such date, the award will be forfeited in its entirety without consideration on July 31, 2029.The number of shares reported reflects the maximum and only number of shares issuable under the award; there is no target, threshold, or maximum range. The reporting person has authorized and designated the named person to file this Form 4 on the reporting person's behalf for indefinite duration. /s/ Judith Matthews 2026-08-04