X0306 4 2021-03-31 0001624322 Business First Bancshares, Inc. BFST 0001734795 MELVILLE DAVID R. III 500 LAUREL STREET, SUITE 101 BATON ROUGE LA 70801 1 1 President and CEO Common Stock 2021-03-31 4 F 0 5294 23.93 D 137024 D Common Stock 2021-04-30 4 M 0 50000 15 A 187024 D Common Stock 2021-04-30 4 F 0 36836 24 D 150188 D Common Stock 2021-05-10 4 M 0 50000 15 A 200188 D Common Stock 2021-05-10 4 F 0 37246 24.28 D 162942 D Stock Options (Right to Buy) 15 2021-04-30 4 M 0 50000 0 D 2021-05-17 Common Stock 50000 50000 D Stock Options (Right to Buy) 15 2021-05-10 4 M 0 50000 0 D 2021-05-17 Common Stock 50000 0 D Includes (a) 4,659 shares of unvested restricted stock granted on 2/1/2020, all of which will vest on 3/31/2022, and (b) 19,082 shares of unvested restricted stock granted on 2/1/2021, 9,399 shares of which will vest on 3/31/2022 and the remaining 9,683 shares will vest on 3/31/2023. Under the terms of the relevant restricted stock grants, the reported shares of unvested restricted stock are subject to forfeiture upon the occurrence of certain events. Includes units of employer stock fund through issuer's 401(k) plan equivalent to approximately 4,851 shares. Stock Options (Right to Buy) vested in four equal installments beginning on the first anniversary of the grant date, May 17, 2011, and ending May 17, 2015. /s/ Heather Roemer, as attorney-in-fact for David R. Melville, III 2021-08-16