NPK International (NPKI) CFO trades options, sells 108,590 shares under 10b5-1 plan

Rhea-AI Filing Summary

NPK International Inc. Senior Vice President and CFO Gregg Piontek reported option exercises and share sales in the company’s stock. On March 4, 2026, he exercised 73,590 non-qualified stock options, acquiring the same number of common shares at a stated exercise price of $4.32 per share. He then sold 73,590 shares at a weighted average price of $14.0979 and a further 35,000 shares at a weighted average price of $14.0169 in open-market transactions. The filing notes that both the option exercise-related sale and the separate 35,000-share sale occurred automatically under a Rule 10b5-1 trading plan adopted on December 3, 2025. Following these transactions, Piontek directly holds 884,326 common shares and indirectly holds 65,000 shares through a trust/IRA arrangement.

Insider Trade Summary

Net Seller: 108,590 shares ($1,528,056)

Net Sell 5 txns

Insider Piontek Gregg

Role Senior Vice President and CFO

Sold 108,590 shs ($1.53M)

Type	Security	Shares	Price	Value
Exercise	Non-Qualified Stock Option (right to buy)	73,590	$0.00	--
Exercise	Common Stock	73,590	$4.32	$318K
Sale	Common Stock	73,590	$14.0979	$1.04M
Sale	Common Stock	35,000	$14.0169	$491K
holding	Common Stock	--	--	--

Holdings After Transaction: Non-Qualified Stock Option (right to buy) — 0 shares (Direct); Common Stock — 992,916 shares (Direct); Common Stock — 65,000 shares (Indirect, by IRA)

Footnotes (1)

1. The reported exercise of 73,590 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025. The price reported is the weighted average price. These options were sold in multiple transactions in the open market at prices ranging from $14.00 to $14.31, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of options sold at each separate price within the range set forth in footnote (2) to this Form 4. The reported sale of 35,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025. The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.68 to $14.31, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4. These shares are indirectly held by Trust.

Form 4 Insider Transactions: What Each Field Means →

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^*

Piontek Gregg

(Last) (First) (Middle)

9320 LAKESIDE BOULEVARD

SUITE 100

(Street)

THE WOODLANDS TX 77381

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
NPK International Inc. [ NPKI ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Senior Vice President and CFO

3. Date of Earliest Transaction (Month/Day/Year)
03/04/2026

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	03/04/2026		M		73,590(1)	A	$4.32	992,916	D
Common Stock	03/04/2026		S		73,590(1)	D	$14.0979(2)	919,326	D
Common Stock	03/04/2026		S		35,000(3)	D	$14.0169(4)	884,326	D
Common Stock								65,000	I	by IRA(5)

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
Non-Qualified Stock Option (right to buy)	$4.32	03/04/2026		M			73,590(1)	06/01/2019	05/19/2026	Common Stock	73,590	$0.0	0	D

Explanation of Responses:

1. The reported exercise of 73,590 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

2. The price reported is the weighted average price. These options were sold in multiple transactions in the open market at prices ranging from $14.00 to $14.31, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of options sold at each separate price within the range set forth in footnote (2) to this Form 4.

3. The reported sale of 35,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

4. The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.68 to $14.31, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

5. These shares are indirectly held by Trust.

	By: M. Celeste Fruge For: Gregg S. Piontek	03/05/2026
	** 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 insider transactions did NPKI CFO Gregg Piontek report on March 4, 2026?

Gregg Piontek reported exercising 73,590 non-qualified stock options and acquiring the same number of common shares at $4.32 per share. He then sold 73,590 shares and an additional 35,000 shares in open-market trades under a pre-arranged Rule 10b5-1 trading plan.

How many NPKI shares did Gregg Piontek sell in this Form 4 filing?

The Form 4 shows total open-market sales of 108,590 NPK International Inc. shares. This includes 73,590 shares related to an option exercise and a separate sale of 35,000 shares, all executed at weighted average prices between approximately $13.68 and $14.31 per share.

What is a Rule 10b5-1 trading plan mentioned in the NPKI Form 4?

A Rule 10b5-1 trading plan is a pre-arranged program allowing insiders to sell shares according to set instructions. The filing states Piontek’s 73,590-share exercise-related sale and separate 35,000-share sale occurred automatically under a plan adopted on December 3, 2025.

How many NPKI shares does Gregg Piontek own after these transactions?

After the reported transactions, Gregg Piontek directly owns 884,326 shares of NPK International Inc. common stock. The filing also notes an additional 65,000 shares held indirectly through a trust or IRA arrangement, reflecting his continued equity stake in the company.

At what prices were Gregg Piontek’s NPKI option exercise and share sales executed?

The options were exercised at $4.32 per share to acquire 73,590 common shares. Subsequent open-market sales occurred at weighted average prices of $14.0979 for 73,590 shares and $14.0169 for 35,000 shares, with actual trade prices ranging between $13.68 and $14.31.

Does the NPKI Form 4 indicate indirect holdings for Gregg Piontek?

Yes. In addition to his direct ownership, the Form 4 reports 65,000 NPK International Inc. shares held indirectly. The filing describes these shares as being held by a trust and in an IRA, indicating a separate account structure from his direct personal holdings.