X0609 4 2026-05-13 0001499422 RBB Bancorp RBB 0001794553 Hanson Diana false 1055 WILSHIRE BLVD SUITE 1200 LOS ANGELES CA 90017 1 Chief Accounting Officer 0 Common Stock, No Par Value 492 D Restricted Stock Units 0.0000 Common Stock 2300 2300 D Restricted Stock Units 0.0000 Common Stock 1255 1255 D There will be no expiration date once restricted stock units vest. These remaining restricted stock units vest in three equal annual installment on 08/19/2026, 08/19/2027 and 08/19/2028 date of grant. The Form 4 has been updated to clarify that grants of RSUs will be settled in Common Stock. These restricted stock units vest in four equal annual installments beginning one year after the 05/13/2026 date of grant. Restricted Stock Units (RSUs) were granted on May 13, 2026. /s/ Diana Hanson 2026-05-15