Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^{F1,F2,F3,F5,F6,F7}	May 25, 2018	S	3,468,136	$40.05	D	4,048,612	I	Held through Silver Lake Sumeru Fund, L.P.
Common Stock^{F1,F2,F4,F5,F6,F7}	May 25, 2018	S	31,864	$40.05	D	35,261	I	Held through Silver Lake Technology Investors Sumeru, L.P.
Common Stock^{F8,F3,F5,F6,F7}	May 25, 2018	J	100,000	—	D	3,948,612	I	Held through Silver Lake Sumeru Fund, L.P.
Common Stock^F8,F6,F7,F9	May 25, 2018	J	100,000	—	A	100,000	I	Held through Silver Lake Technology Associates Sumeru, L.P.

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1Represents shares of BlackLine, Inc.'s (the "Issuer") Common Stock sold in an underwritten secondary offering.
F2Represents the sale price to the underwriter in the secondary offering of $40.05 per share.
F3Silver 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.
F4SLG 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.
F5As 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.
F6Each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such Reporting Person's pecuniary interest therein, if any.
F7Pursuant 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.
F8Represents 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.
F9SLT 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.

Remarks

Pursuant to the Stockholders Agreement, dated as of October 27, 2016, by and among the Issuer, SLSF, SLTI, Iconiq Strategic Partners, L.P., Therese Tucker and Mario Spanicciati, SLSF and SLTI will have the right to appoint or nominate for election to the Issuer's board of directors, as applicable, (i) seven directors of up to a 13 member board for so long as the Silver Lake Sumeru Shares constitute more than 35% of the total number of shares of the Issuer's common stock then outstanding; (ii) six directors for so long as the Silver Lake Sumeru Shares constitute 35% or less, but more than 25% of the total number of shares of the Issuer's common stock then outstanding; (iii) three directors for so long as the Silver Lake Sumeru Shares constitute 25% or less, but more than 20% of the total number of shares of the Issuer's common stock then outstanding; (iv) two directors for so long as the Silver Lake Sumeru Shares constitute 20% or less, but more than 10% of the total number of shares of the Issuer's common stock then outstanding; and (v) one director for so long as the Silver Lake Sumeru Shares constitute 10% or less but at least 5% of the total number of shares of the Issuer's common stock then outstanding. The Reporting Persons are jointly filing this Form 4 pursuant to Rule 16a-3(j) under the Exchange Act.