[8-K] NEWMARKET CORP Reports Material Event

Rhea-AI Filing Summary

NewMarket Corporation reported that Controller and Principal Accounting Officer Ann P. Pietrantoni will resign, effective November 26, 2025. The company received notice of her decision on October 31, 2025.

Upon her departure, Vice President and Chief Financial Officer Timothy K. Fitzgerald will assume the role of Principal Accounting Officer on an interim basis. The company stated that the resignation is not the result of any dispute or disagreement regarding operations, policies, or practices.

NEWMARKET CORP false 0001282637 0001282637 2025-10-31 2025-10-31

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 31, 2025

NEWMARKET CORPORATION

(Exact name of registrant as specified in its charter)

Virginia		1-32190		20-0812170
(State or other jurisdiction of incorporation)		(Commission File Number)		(IRS Employer Identification No.)

330 South Fourth Street,
Richmond, Virginia		23219
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code: (804) 788-5000

Not applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, without par value		NEU		New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange Act of 1934.

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

On October 31, 2025, NewMarket Corporation (the Company) received notice that Ann P. Pietrantoni, the Company’s Controller and Principal Accounting Officer, is resigning from the Company to pursue other opportunities. Mrs. Pietrantoni’s last day with the Company will be November 26, 2025. Her resignation is not the result of any dispute or disagreement with the Company on any matter relating to the Company’s operations, policies or practices.

Upon Mrs. Pietrantoni’s departure, Timothy K. Fitzgerald, the Company’s Vice President and Chief Financial Officer, will assume the role of the Company’s Principal Accounting Officer on an interim basis. Additional information regarding Mr. Fitzgerald can be found in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, under the heading “Information about our Executive Officers.”

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: November 5, 2025

NEWMARKET CORPORATION
By:		/s/ Timothy K. Fitzgerald
		Timothy K. Fitzgerald
		Vice President and Chief Financial Officer

FAQ

What did NewMarket (NEU) announce in this 8-K?

The company announced the resignation of its Controller and Principal Accounting Officer, Ann P. Pietrantoni, effective November 26, 2025.

When is Ann P. Pietrantoni’s last day at NewMarket (NEU)?

Her last day will be November 26, 2025.

Did NewMarket (NEU) cite any disagreements related to the resignation?

No. The company stated the resignation is not due to any dispute or disagreement regarding operations, policies, or practices.

Who will serve as interim Principal Accounting Officer at NewMarket (NEU)?

Vice President and Chief Financial Officer Timothy K. Fitzgerald will serve as interim Principal Accounting Officer.

When did NewMarket (NEU) receive notice of the resignation?

The company received notice on October 31, 2025.

Where can I find more information about Timothy K. Fitzgerald?

Additional information is available in the company’s Form 10-K for the year ended December 31, 2024, under “Information about our Executive Officers.”