X0306 4 2020-03-12 0001624322 Business First Bancshares, Inc. BFST 0001734848 SHAMIEH FAYEZ K. 500 LAUREL STREET, SUITE 101 BATON ROUGE LA 70801 1 COMMON STOCK 2020-03-12 4 P 0 10000 16.29 A 44058 D COMMON STOCK 2020-03-13 4 P 0 6238 15.20 A 50296 D This transaction was executed in multiple trades at prices ranging from $15.9176 to $17.1724. The price reported above reflect the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. This transaction was executed in multiple trades at prices ranging from $15.1512 to $15.4025. The price reported above reflect the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. /s/ Heather Roemer, as attorney-in-fact for Fayez K. Shamieh 2020-03-16