BL · Blackline, Inc. · Insider Trading

The options became exercisable based on the following vesting schedule: The shares subject to the option vested in 4 equal, annual installments beginning on the one-year anniversary of the grant date, subject to the reporting person's continued service through each applicable vesting date.

The sale price represents the weighted-average price of shares sold ranging from $31.78 to $32.14 per share, and is rounded to the nearest tenth of a cent. 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 options became exercisable based on the following vesting schedule: The shares subject to the option vested in 4 equal, annual installments beginning on the one-year anniversary of the grant date, subject to the reporting person's continued service through each applicable vesting date.

The options became exercisable based on the following vesting schedule: The shares subject to the option vested in 4 equal, annual installments beginning on the one-year anniversary of the grant date, subject to the reporting person's continued service through each applicable vesting date.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The transaction reported on this Form 4 was effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on February 19, 2026.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

Includes 459 shares acquired on May 8, 2026, through the Issuer's Employee Stock Purchase Plan in a transaction that was exempt under both Rule 16b-3(d) and Rule 16b-3(c).

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

Includes 459 shares acquired on May 8, 2026, through the Issuer's Employee Stock Purchase Plan in a transaction that was exempt under both Rule 16b-3(d) and Rule 16b-3(c).

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

Includes 459 shares acquired on May 8, 2026, through the Issuer's Employee Stock Purchase Plan in a transaction that was exempt under both Rule 16b-3(d) and Rule 16b-3(c).

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

Includes 459 shares acquired on May 8, 2026, through the Issuer's Employee Stock Purchase Plan in a transaction that was exempt under both Rule 16b-3(d) and Rule 16b-3(c).

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.

The reported shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units.