X0306 4 2018-10-19 0 0001459839 SI-BONE, Inc. SIBN 0001592730 Petersen Timothy C/O ARBORETUM VENTURES 303 DETROIT STREET, SUITE 301 ANN ARBOR MI 48104 1 0 0 0 Common Stock 2018-10-19 4 C 0 1495036 A 1495036 I By Arboretum Ventures IV, LP Common Stock 2018-10-19 4 P 0 200000 15.00 A 1695036 I By Arboretum Ventures IV, LP Series 7 Preferred Stock 2018-10-19 4 C 0 1495036 D Common Stock 1495036 0 I By Arboretum Ventures IV, LP The Issuer's Series 7 Preferred Stock automatically converted into an equal number of shares of Issuer's common stock immediately upon the closing of the Issuer's initial public offering and has no expiration date. Shares held by Arboretum Ventures IV, LP ("AV IV"). Arboretum Investment Manager IV, LLC ("AIM IV") serves as the general partner of AV IV. Jan Garfinkle, Timothy B. Petersen, a member of the Issuer's board of directors, and Paul McCreadie are managing members of AIM IV and share voting and dispositive power with regard to these shares and therefore each of the foregoing managing members may be deemed to have the same powers with respect to such shares. Mr. Petersen disclaims beneficial ownership of such shares except to the extent of his proportionate pecuniary interest, if any. /s/ Michael A. Pisetsky, Attorney-in-Fact for Timothy B. Petersen 2018-10-19