X0306 4 2019-08-08 0 0001666134 BLACKLINE, INC. BL 0001183627 PRAGER MORGAN KAROLE 21300 VICTORY BLVD 12TH FLOOR WOODLAND HILLS CA 91367 0 1 0 0 Chief Legal and Administrative Common Stock 2019-08-08 4 M 0 10000 14.50 A 34053 D Common Stock 2019-08-08 4 S 0 10000 54.7634 D 24053 D Stock Option (right to buy) 14.50 2019-08-08 4 M 0 10000 0.00 D 2025-05-29 Common Stock 10000 90000 D The sale transaction reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 23, 2019. The sale price represents the weighted-average price of shares sold ranging from $54.11 to $54.90 per share. Upon request by the 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 shares subject to the option vest in 4 equal, annual installments beginning on the one year anniversary of May 30, 2015. /s/ Karole Morgan-Prager, attorney-in-fact 2019-08-12