X0306 4 2017-03-16 1 0001574815 BMC STOCK HOLDINGS, INC. BMCH 0001428776 GORES GROUP, LLC 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001580715 GORES BUILDING HOLDINGS, LLC 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001580718 GLENDON SATURN HOLDINGS, LLC 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001407447 GORES CAPITAL PARTNERS II LP 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001580716 GORES CAPITAL ADVISORS II, LLC 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001322454 Gores Alec E 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001438067 Stone Mark 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001583026 DIGGINS VANCE W. 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001634908 GONI FERNANDO 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 0001247300 YAGER STEVEN 9800 WILSHIRE BLVD. BEVERLY HILLS CA 90212 0 0 1 0 Common Stock, par value $0.01 per share 2017-03-16 4 S 0 2484078 21.06 D 4616197 I See Footnotes Common Stock, par value $0.01 per share 2017-03-16 4 S 0 115922 21.06 D 215420 I See Footnotes Represents shares of BMC Stock Holdings, Inc.'s (the "Issuer") common stock sold in an underwritten secondary offering. Represents the offering price to the underwriters in the secondary offering of $21.06 per share. These shares are held of record by Gores Building Holdings, LLC ("Gores Holdings"). These shares are held of record by Glendon Saturn Holdings, LLC ("Glendon Saturn"). The Gores Group, LLC ("Gores") is the manager of Gores Holdings and Glendon Saturn and Alec E. Gores is the manager of Gores. Gores Capital Partners II, L.P. ("Gores II") is the controlling member of Gores Holdings. Gores Capital Advisors II, LLC ("Gores Advisors") is the general partner of Gores II. Gores is the manager of Gores Advisors. Gores has a five member investment committee that has voting and dispositive authority over the common stock held of record by Gores Holdings and Glendon Saturn. (continued from Footnote 5) The members of the investment committee include Alec E. Gores, Mark R. Stone, Vance W. Diggins, Fernando Goni and Steven C. Yager. Each of the foregoing persons may be deemed to share voting and dispositive power with respect to the shares he1d of record by Gores Holdings and Glendon Saturn. None of the members of the investment committee, acting alone, has voting or dispositive power over any shares. Each of the reporting persons disclaims beneficial ownership of the shares except to the extent of such person's pecuniary interest therein. /s/ Eric Hattler by power of attorney for The Gores Group, LLC 2017-03-20 /s/ Eric Hattler by power of attorney for Gores Building Holdings, LLC 2017-03-20 /s/ Eric Hattler by power of attorney for Glendon Saturn Holdings, LLC 2017-03-20 /s/ Eric Hattler by power of attorney for Gores Capital Partners II, L.P. 2017-03-20 /s/ Eric Hattler by power of attorney for Gores Capital Advisors II, LLC 2017-03-20 /s/ Eric Hattler by power of attorney for Alec E. Gores 2017-03-20 /s/ Eric Hattler by power of attorney for Mark R. Stone 2017-03-20 /s/ Eric Hattler by power of attorney for Fernando Goni 2017-03-20 /s/ Eric Hattler by power of attorney for Vance W. Diggins 2017-03-20 /s/ Eric Hattler by power of attorney for Steven C. Yager 2017-03-20