X0508 4 2024-02-21 0 0001702750 BYLINE BANCORP, INC. BY 0001709907 DEL VALLE PEROCHENA ANTONIO 180 N. LASALLE ST. SUITE 300 CHICAGO IL 60601 1 0 1 0 0 Common stock 2024-02-21 4 P 0 10000 20.9366 A 11819701 I By MBG Investors I, L.P. Common stock 2024-02-22 4 P 0 5444 20.917 A 11825145 I By MBG Investors I, L.P. Mr. Antonio del Valle Perochena is the general partner of MBG Investors I, L.P. and possesses sole voting and investment power with respect to the shares of common stock held by MBG Investors I, L.P. Mr. del Valle Perochena owns 16.68% of the partnership interests of MBG Investors I, L.P. Mr. del Valle Perochena disclaims beneficial ownership of such shares of common stock except to the extent of his pecuniary interest therein, and this report shall not be deemed an admission that he is the beneficial owner of such disclaimed shares of common stock for purposes of Section 16 or for any other purpose. The address for MBG Investors I, L.P. is 365 Bay Street, Suite 800, M5H2V1 Toronto, Ontario, Canada. /s/ Ana Casanueva, Attorney-in-fact for Antonio del Valle Perochena 2024-02-23