X0306 4 2019-06-13 0001624322 Business First Bancshares, Inc. BFST 0001759712 Vascocu Norman Jerome Sr 500 LAUREL STREET, SUITE 101 BATON ROUGE LA 70801 1 COMMON STOCK 2019-06-13 4 S 0 500 24.64 D 68281 D COMMON STOCK 2019-06-14 4 S 0 448 24.72 D 67773 D COMMON STOCK 2019-06-17 4 S 0 1029 25.05 D 66744 D COMMON STOCK 2019-06-18 4 S 0 470 25.04 D 66274 D COMMON STOCK 2019-06-19 4 S 0 500 25.11 D 65774 D COMMON STOCK 2019-06-20 4 S 0 1314 25.12 D 64460 D COMMON STOCK 2019-06-21 4 S 0 1400 25.21 D 63060 D COMMON STOCK 2019-06-24 4 S 0 1090 25.25 D 61970 D COMMON STOCK 2019-06-25 4 S 0 1501 25.37 D 60469 D COMMON STOCK 2019-06-26 4 S 0 1182 25.26 D 59287 D COMMON STOCK 2019-06-27 4 S 0 3199 25.37 D 56088 D COMMON STOCK 2019-06-28 4 S 0 5000 25.42 D 51088 D COMMON STOCK 2019-07-01 4 S 0 800 25.67 D 50288 D COMMON STOCK 2019-07-02 4 S 0 11567 25.50 D 38721 D This transaction was executed in multiple trades at prices ranging from $24.57 to $24.66. 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 $24.55 to $25.09. 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 $24.92 to $25.20. 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 $24.90 to $25.24. 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 $25.01 to $25.25. 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 $24.98 to $25.30. 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 $24.97 to $25.40. 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 $25.15 to $25.40. 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 $25.07 to $25.60. 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 $24.96 to $25.46. 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 $25.20 to $25.45. 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 $25.35 to $25.49. 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 $25.48 to $25.75. 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 $25.15 to $25.53. 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 2019-09-11