[Form 4] OMNICOM GROUP INC. Insider Trading Activity

Rhea-AI Filing Summary

Mark D. Gerstein, a director of Omnicom Group Inc. (OMC), reported two acquisitions of common stock on 10/01/2025 through elective deferrals under the Omnicom Group Inc. 2021 Incentive Award Plan. He elected to defer 628.6 shares (per note 1) and 275.97 shares (quarterly retainer, per note 2), both recorded as acquisitions at $0 price because they are deferred awards. The filing shows his beneficial ownership after the transactions as 12,755.07 and 13,031.04 shares, and notes that dividends on deferred shares were reinvested and credited on July 9, 2025.

Insights

Corporate Governance / Insider Transactions Analyst

Director deferred equity awards totaling 904.57 shares via the company plan on 10/01/2025.

The filing records two deferral elections under the 2021 Incentive Award Plan: 628.6 shares (award deferral) and 275.97 shares (quarterly retainer deferral). Both transactions are listed as acquisitions at $0 because they reflect deferred compensation rather than open-market purchases.

The report also discloses that dividends on deferred shares were reinvested and credited on July 9, 2025, which increased the deferred share balance. This is a routine disclosure of director compensation elections and does not by itself indicate a change in control or a market transaction.

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).

1. Name and Address of Reporting Person^*

Gerstein Mark D

(Last) (First) (Middle)

C/O OMNICOM GROUP INC.

280 PARK AVENUE

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
OMNICOM GROUP INC. [ OMC ]

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)
10/01/2025

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, par value $0.15 per share	10/01/2025		A		628.6(1)	A	$0	12,755.07(3)	D
Common Stock, par value $0.15 per share	10/01/2025		A		275.97(2)	A	$0	13,031.04(3)	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 reporting person elected to defer receipt of these shares under the terms of the Omnicom Group Inc. 2021 Incentive Award Plan.

2. The reporting person elected to defer receipt of these shares, which represent a quarterly payment of his annual retainer, under the terms of the Omnicom Group Inc. 2021 Incentive Award Plan.

3. Includes dividends on deferred shares that are reinvested in company stock, credited on July 9, 2025.

	/s/ Eric J. Cleary, Attorney in Fact for Mark D. Gerstein	10/03/2025
	** 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 transactions did Mark D. Gerstein report on the Form 4 for OMC?

He reported elective deferrals of 628.6 shares and 275.97 shares on 10/01/2025 under the 2021 Incentive Award Plan.

Were the reported OMC shares acquired at market price?

No. Both entries are recorded as acquisitions at $0 because they are deferred awards rather than open-market purchases.

How many shares did Gerstein beneficially own after the reported transactions?

The filing lists beneficial ownership amounts of 12,755.07 and 13,031.04 shares following the reported transactions.

Did the Form 4 disclose any dividend activity related to the deferred shares?

Yes. The filing states that dividends on deferred shares were reinvested in company stock and credited on July 9, 2025.

What is the reporting person’s relationship to Omnicom?

Mark D. Gerstein is reported as a Director of Omnicom Group Inc.