[Form 4] DONALDSON Co INC Insider Trading Activity

Rhea-AI Filing Summary

Richard B. Lewis, an officer (President) of DONALDSON Co. Inc. (DCI), reported several transactions on 10/01/2025–10/02/2025. He acquired 13,500 shares on 10/02/2025 at $28 per share under transaction code M, and exercised 42,100 employee stock options with an exercise price of $82.08 (transaction code A, dated 10/01/2025). Following the reported activity, he beneficially owned 53,279 shares in total, including holdings in a Benefit Plan Trust (832 and 3,866 shares listed as indirect). The filing notes the $28-strike options granted on 10/02/2025 were fully vested, while the exercised $82.08-strike option vests in three equal annual installments beginning 10/01/2026. The form is signed by an attorney-in-fact on 10/03/2025.

Positive

• Acquired 13,500 shares at $28, increasing direct ownership
• Exercised 42,100 employee stock options, converting options into common stock
• Beneficial ownership reported at 53,279 shares following transactions

Negative

• Exercise price of $82.08 for 42,100 options implies prior grant at a higher strike than the $28 purchase price
• Vesting of the $82.08-strike option occurs in three installments starting 10/01/2026, delaying full ownership

Insights

Corporate Insider Transactions Analyst

Insider exercised and bought options increasing direct holdings to 53,279 shares.

The report shows a net increase in reported holdings through an exercise of 42,100 options at an $82.08 strike and an acquisition of 13,500 shares at $28 per share on 10/01–10/02/2025. These are standard Section 16 transactions: the exercise created 42,100 new shares and the separate purchase added 13,500.

This matters to investors because insider option exercises and open market purchases change the insider's reported economic exposure and the company’s outstanding shares; the filing also documents vesting schedules that affect future potential dilution, specifically installments beginning 10/01/2026.

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^*

Lewis Richard Brent

(Last) (First) (Middle)

1400 WEST 94TH STREET

(Street)

BLOOMINGTON MN 55413

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
DONALDSON Co INC [ DCI ]

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

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

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								832	I	By Benefit Plan Trust.
Common Stock								3,866	I	By Benefit Plan Trust
Common Stock	10/02/2025		M		13,500	A	$28	53,279	D
Common Stock	10/02/2025		F		8,982	D	$82.08	44,297	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
Employee Stock Option (right to buy)	$82.08	10/01/2025		A		42,100		(1)	10/01/2035	Common Stock	42,100	$0	42,100	D
Employee Stock Option (right to buy)	$28	10/02/2025		M			13,500	(2)	12/17/2025	Common Stock	13,500	$0	0	D

Explanation of Responses:

1. The option vests in three equal annual installments beginning on October 1, 2026.

2. Fully vested

Remarks:

	/s/ Amy C. Becker, Attorney-in-fact for Richard B. Lewis	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 Richard B. Lewis report for DCI?

He reported exercising 42,100 options at a $82.08 exercise price and acquiring 13,500 shares at $28 on 10/01–10/02/2025.

How many DCI shares does the reporting person beneficially own after the transactions?

The filing reports a total beneficial ownership of 53,279 shares following the reported transactions.

Are any of the reported options unvested?

Yes. The filing states the $82.08-strike option vests in three equal annual installments beginning on 10/01/2026; the $28-strike option granted on 10/02/2025 is noted as fully vested.

Who signed the Form 4 and when?

The Form 4 is signed by Amy C. Becker, Attorney-in-fact for Richard B. Lewis on 10/03/2025.

Did the filing report indirect holdings?

Yes. The filing lists indirect holdings in a Benefit Plan Trust totaling 4,698 shares (832 and 3,866 entries).