BLACKLINE, INC. — Director's Dealing 2018

May 26, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BLACKLINE, INC. (BL)
CIK: 0001666134
Period of Report: 2018-05-25

Reporting Person: SLTA Sumeru (GP), L.L.C. (Director, 10% Owner)
Reporting Person: Silver Lake Group, L.L.C. (Director, 10% Owner)
Reporting Person: Silver Lake Technology Associates Sumeru, L.P. (Director, 10% Owner)
Reporting Person: Silver Lake Sumeru Fund LP (Director, 10% Owner)
Reporting Person: Silver Lake Technology Investors Sumeru, L.P. (Director, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-25	Common Stock	S	3468136	$40.05	Disposed	4048612	Indirect
2018-05-25	Common Stock	S	31864	$40.05	Disposed	35261	Indirect
2018-05-25	Common Stock	J	100000	—	Disposed	3948612	Indirect
2018-05-25	Common Stock	J	100000	—	Acquired	100000	Indirect

Footnotes

F1: Represents shares of BlackLine, Inc.'s (the "Issuer") Common Stock sold in an underwritten secondary offering.

F2: Represents the sale price to the underwriter in the secondary offering of $40.05 per share.

F3: Silver Lake Group, L.L.C. ("SLG") is the managing member of SLTA Sumeru (GP), L.L.C. ("SLTA"), which is the general partner of Silver Lake Technology Associates Sumeru, L.P. ("SLT LP"), which is the general partner of Silver Lake Sumeru Fund, L.P. ("SLSF"), which directly holds these shares of Common Stock.

F4: SLG is the managing member of SLTA, which is the general partner of SLT LP, which is the general partner of Silver Lake Technology Investors Sumeru, L.P. ("SLTI", and collectively with SLG, SLTA, SLT LP and SLSF, the "Reporting Persons"), which directly holds these shares of Common Stock.

F5: As the general partner of each of SLSF and SLTI, SLT LP may be deemed to share voting and dispositive power with respect to the Common Stock directly held by SLSF and SLTI (the "Silver Lake Sumeru Shares"). As the general partner of SLT LP, SLTA may be deemed to share voting and dispositive power with respect to the Silver Lake Sumeru Shares. As the managing member of SLTA, SLG may be deemed to share voting and dispositive power with respect to the Silver Lake Sumeru Shares.

F6: Each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein, if any.

F7: Pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), this filing shall not be deemed an admission that the Reporting Persons are, for purposes of Section 16 of the Exchange Act or otherwise, the beneficial owners of any equity securities in excess of their respective pecuniary interests.

F8: Represents a distribution by SLSF of shares of Common Stock of the Issuer to its general partner, SLT LP. These shares are subject to a 45-day lock-up from the date of the underwritten secondary offering.

F9: SLT LP directly holds these shares of Common Stock (the "SLT LP Shares"). As the general partner of SLT LP, SLTA may be deemed to share voting and dispositive power with respect to the SLT LP Shares. As the managing member of SLTA, SLG may be deemed to share voting and dispositive power with respect to the SLT LP Shares.