X0306 4 2020-08-27 0 0001666134 BLACKLINE, INC. BL 0001688365 Tucker Therese 21300 VICTORY BLVD., 12TH FLOOR WOODLAND HILLS CA 91367 1 1 0 0 Chief Executive Officer Common Stock 2020-08-27 4 S 0 96173 85.3212 D 2502309 I Brian & Therese Tucker Living Trust Common Stock 2020-08-27 4 S 0 47606 86.5988 D 2454703 I Brian & Therese Tucker Living Trust Common Stock 2020-08-27 4 S 0 11821 87.1423 D 2442882 I Brian & Therese Tucker Living Trust Common Stock 158594 D Common Stock 874128 I Tucker Legacy Trust Common Stock 577200 I Isaac Tucker 2012 Irrevocable Trust Common Stock 577200 I Roseanna Tucker 2012 Irrevocable Trust Common Stock 250916 I Tucker Seimetz Safety Net Trust Common Stock 54074 I Claire Seimetz 2015 Trust The sale price represents the weighted-average price of shares sold ranging from $85.00 to $85.99 per share. Upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. The sale price represents the weighted-average price of shares sold ranging from $86.00 to $86.995 per share. Upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. The sale price represents the weighted-average price of shares sold ranging from $87.00 to $87.335 per share. Upon request by the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. /s/ Karole Morgan-Prager, Attorney-in-Fact 2020-08-28