[Form 4] BLACKLINE, INC. Insider Trading Activity

Rhea-AI Filing Summary

BlackLine (BL) director reported an open‑market sale under a Rule 10b5-1 plan. On 10/27/2025, the reporting person sold 910 shares of common stock at $55 per share, coded “S”. The filing notes the plan was adopted on November 21, 2024.

Following the transaction, the reporting person beneficially owned 58,636 shares (direct) and 41,835 shares (indirect) through the ETU Rustic Canyon Trust. The form was filed by one reporting person, identified as a Director.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Unterman Thomas

(Last) (First) (Middle)

21300 VICTORY BLVD., 12TH FLOOR

(Street)

WOODLAND HILLS CA 91367

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BLACKLINE, INC. [ BL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
10/27/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	10/27/2025		S(1)		910	D	$55	41,835	I	ETU Rustic Canyon Trust
Common Stock								58,636	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The transaction reported on this Form 4 was effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 21, 2024.

	/s/ Karole Morgan-Prager, Attorney-in-Fact	10/28/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did BlackLine (BL) disclose in this Form 4?

A Director sold 910 shares of common stock at $55 on 10/27/2025 under a Rule 10b5-1 plan.

How many BlackLine (BL) shares does the insider hold after the sale?

Post-transaction holdings are 58,636 shares direct and 41,835 shares indirect via the ETU Rustic Canyon Trust.

Was the BlackLine (BL) trade under a 10b5-1 plan?

Yes. The filing states the trade was effectuated under a Rule 10b5-1 trading plan adopted on November 21, 2024.

What was the transaction code in the BlackLine (BL) Form 4?

The transaction code was S, indicating an open-market or private sale of non-derivative securities.

What is the insider’s relationship to BlackLine (BL)?

The reporting person is a Director of BlackLine, Inc.

How was ownership categorized after the transaction?

Ownership is listed as Direct (D) for 58,636 shares and Indirect (I) for 41,835 shares through the ETU Rustic Canyon Trust.