X0306 4 2019-06-10 0 0001764925 Slack Technologies, Inc. WORK 0001778886 Social Capital Holdings Inc. C/O SOCIAL CAPITAL 120 HAWTHORNE AVENUE PALO ALTO CA 94301 0 0 1 0 0001568269 Social Capital Partnership GP II, Ltd. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO 94070 0 0 1 0 0001567969 Social Capital Partnership II, L.P. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 0001567974 Social Capital Partnership Principals Fund II, L.P. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 0001568270 Social Capital Partnership GP II, L.P. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 0001631888 Social Capital Partnership III, L.P. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 0001631891 Social Capital Partnership Principals Fund III, L.P. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 0001778963 Social Capital Partnership GP III, Ltd C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 0001631886 Social Capital Partnership GP III, L.P. C/O SOCIAL CAPITAL HOLDINGS INC. 120 HAWTHORNE AVENUE PALO ALTO CA 94070 0 0 1 0 Class A Common Stock 2019-06-10 4 C 0 625344 A 625344 I See Footnotes Class A Common Stock 2019-06-10 4 C 0 10822515 A 10822515 I See Footnotes Class A Common Stock 2019-06-10 4 C 0 1265482 A 1265482 I See Footnotes Class B Common Stock 2019-06-10 4 C 0 625344 0.00 D Class A Common Stock 625344 1876030 I See Footnotes Class B Common Stock 2019-06-10 4 C 0 10822515 0.00 D Class A Common Stock 10822515 32467545 I See Footnotes Class B Common Stock 2019-06-10 4 C 0 1265482 0.00 D Class A Common Stock 1265482 3796446 I See Footnotes Each share of Class B Common Stock is convertible into one share of Class A Common Stock at the option of the Reporting Person and has no expiration date. The shares are held by The Social+Capital Partnership III, L.P. (the "SC III") for itself and as nominee for The Social+Capital Partnership Principals Fund III, L.P. (the "Principals III"). The Social+Capital Partnership GP III, Ltd. (the "GP III Ltd.") is the general partner of The Social+Capital Partnership GP III, L.P. (the "GP III LP"), which is the general partner of SC III. The sole member of GP III Ltd. is Social Capital Holdings Inc. ("SC Holdings"). GP III Ltd. has sole voting and dispositive power with regard to the shares held by SC III. The shares are held by The Social+Capital Partnership II, L.P., (the "SC II") for itself and as nominee for certain other individuals and entities. The Social+Capital Partnership GP II, Ltd.(the "GP II Ltd.") is the general partner of The Social+Capital Partnership GP II, L.P. (the "GP II LP"), which is the general partner of SC II. The sole member of GP II Ltd. is SC Holdings. GP II Ltd. has sole voting and dispositive power with regard to the shares held by SC II. The shares are held by The Social+Capital Partnership Opportunities Fund, L.P., (the "SCP Opportunities Fund"). The Social+Capital Partnership Opportunities Fund GP, Ltd. (the "Opportunities GP Ltd.") is the general partner of The Social+Capital Partnership Opportunities Fund GP, L.P. (the "Opportunities GP LP"), which is the general partner of SCP Opportunities Fund. The sole member of Opportunities GP Ltd. is SC Holdings. Opportunities GP Ltd. has sole voting and dispositive power with regard to the shares held by SCP Opportunities Fund. Chamath Palihapitiya is a director of the Issuer and the Chief Executive Officer of SC Holdings and holds voting and dispositive power over shares controlled by GP II Ltd., GP III Ltd., and Opportunities GP Ltd. This Form 4 is the first of two Form 4s filed relating to the same event. Combined, the two reports report the holdings for the following reporting persons: Social Capital Holdings Inc., The Social+Capital Partnership II, L.P., The Social+Capital Partnership Principals Fund II, L.P., The Social+Capital Partnership GP II, Ltd., The Social+Capital Partnership GP II, L.P., The Social+Capital Partnership III, L.P., The Social+Capital Partnership Principals Fund III, L.P., The Social+Capital Partnership GP III, Ltd., The Social+Capital Partnership GP III, L.P., The Social+Capital Partnership Opportunities Fund, L.P., The Social+Capital Partnership Opportunities Fund GP, Ltd. and The Social+Capital Partnership Opportunities Fund GP, L.P. This Form 4 has been split into two filings because there are more than 10 reporting persons in total, and the SEC's EDGAR filing system limits a single Form 4 to a maximum of 10 reporting persons. Each Form 4 is filed by designated filer Social Capital Holdings Inc. /s/Chamath Palihapitiya 2019-06-12