X0306 4 2017-02-22 0 0001702750 BYLINE BANCORP, INC. BY 0001214993 HERENCIA ROBERTO R C/O BYLINE BANCORP, INC. 180 NORTH LASALLE STREET SUITE 300 CHICAGO IL 60601 1 0 0 0 Common Stock 2017-02-22 4 P 0 2160 16.25 A 81435 D Common Stock 2017-02-22 4 P 0 10147 16.25 A 10147 I By Roberto Herencia Inc. Defined Benefit Plan Common Stock 2017-07-06 4 P 0 22500 19.00 A 103935 D Represents shares of common stock of the issuer's predecessor, Byline Bancorp, Inc., an Illinois corporation ("Byline Illinois") purchased by Mr. Herencia from another stockholder in a private transaction prior to Byline Illinois's reincorporation in Delaware on June 16, 2017 by way of merger with the issuer. The number of shares of common stock, par value $0.01 per share ("Common Stock"), purchased and the price per share of Common Stock are presented after giving effect to the exchange ratio in the reincorporation merger of one share of the issuer's Common Stock for every five shares of Byline Illinois common stock held by each holder, subject to a cash payment in lieu of fractional shares. Shares of Common Stock are held through the Roberto Herencia Inc. Defined Benefit Plan. Mr Herencia possesses the voting and investment power with respect to the shares of Common Stock held by the Roberto Herencia Inc. Defined Benefit Plan. Represents shares of Common Stock of the issuer purchased through a reserved share program in connection with the initial public offering of the Common Stock, which closed on July 6, 2017. /s/ Roberto R. Herencia 2017-07-06