X0407 4 2023-06-12 1 0001499422 RBB Bancorp RBB 0001711554 Lin Paul 1055 WILSHIRE BLVD SUITE 1200 LOS ANGELES CA 90017 1 Former Director 0 Common Stock, No Par Value 2023-06-09 4 M 0 600 0 A 2450 D Option (right to buy) 11.1498 2023-05-15 Common Stock 3490 0 D Option (right to buy) 13.2098 2024-05-21 Common Stock 10250 0 D Option (right to buy) 17.0800 2025-05-20 Common Stock 10000 0 D Option (right to buy) 18.2500 2026-05-17 Common Stock 10000 0 D Restricted Stock Units 0 2023-06-09 4 M 0 600 0 D Restricted Stock Units 600 0 D These options vest in three equal annual installments beginning one year after the 05/15/2013 date of grant. These options vest in three equal annual installments beginning one year after the 05/21/2014 date of grant. These options vest in three equal annual installments beginning one year after the 05/20/2015 date of grant. These options vest in three equal annual installments beginning one year after the 05/17/2016 date of grant. There will be no expiration date once restricted stock units vest. These restricted stock units vest in two installments: 800 at 01/18/2023 and 600 at 01/18/2024. After the 2023 Annual Shareholder Meeting, Mr. Lin became a former director. The Board of Directors approved the early vesting of Mr. Lin's 600 RSUs to be released on 6/9/2023 instead of the scheduled vesting on 1/18/2024. /s/ Paul Lin 2023-06-12