NPK International (NPKI) CFO sells 15,000 shares under 10b5-1 plan

Rhea-AI Filing Summary

NPK International Inc. Senior Vice President and CFO Gregg Piontek reported an open‑market sale of 15,000 shares of common stock on March 25, 2026 at a weighted average price of $15.0256 per share, with trades executed between $15.00 and $15.12.

The transaction was carried out automatically under a pre‑arranged Rule 10b5‑1 trading plan adopted on December 3, 2025. Following this sale, Piontek directly holds 869,326 shares and indirectly holds 65,000 shares through an IRA.

Insider Trade Summary 10b5-1

Net Seller: 15,000 shares ($225,384)

Net Sell 2 txns

Insider Piontek Gregg

Role Senior Vice President and CFO

Sold 15,000 shs ($225K)

Type	Security	Shares	Price	Value
Sale	Common Stock	15,000	$15.0256	$225K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 869,326 shares (Direct); Common Stock — 65,000 shares (Indirect, by IRA)

Footnotes (1)

1. The reported sale of 15,000 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 $15.00 to $15.12, 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 TEXAS 77381

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/25/2026

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

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

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

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	03/25/2026		S		15,000(1)	D	$15.0256(2)	869,326	D
Common Stock								65,000	I	by IRA(3)

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 reported sale of 15,000 shares 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 shares were sold in multiple transactions in the open market at prices ranging from $15.00 to $15.12, 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.

3. These shares are indirectly held by Trust.

Remarks:

	By: M. Celeste Fruge For: Gregg S. Piontek	03/26/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What did NPKI executive Gregg Piontek report in this Form 4?

Gregg Piontek, Senior Vice President and CFO of NPK International Inc. (NPKI), reported selling 15,000 shares of common stock. The filing details an open-market sale executed under a pre-arranged Rule 10b5-1 trading plan, along with his updated direct and indirect share holdings.

How many NPKI shares did the CFO sell and at what price?

The CFO sold 15,000 shares of NPK International Inc. common stock at a weighted average price of $15.0256. The shares were sold in multiple open-market trades, with individual prices ranging from $15.00 to $15.12 per share, according to the Form 4 disclosure.

Was the NPKI CFO’s share sale made under a Rule 10b5-1 plan?

Yes. The Form 4 states the 15,000-share sale occurred automatically under a Rule 10b5-1 trading plan. This plan was adopted by Gregg Piontek on December 3, 2025, indicating the transactions were pre-scheduled rather than timed discretionarily around short-term market movements.

How many NPKI shares does Gregg Piontek hold after this transaction?

After the reported sale, Gregg Piontek directly owns 869,326 shares of NPK International Inc. common stock. The Form 4 also shows an additional 65,000 shares held indirectly through an IRA, providing a view of both his direct and indirect beneficial ownership positions.

Does this NPKI Form 4 involve any derivative securities or option exercises?

No. The reported activity concerns only non-derivative common stock transactions. The Form 4’s derivative summary is empty, and there are no option exercises, conversions, or other derivative-related transactions disclosed in this filing for Gregg Piontek.

What trading range is disclosed for the NPKI shares sold by the CFO?

The filing notes that the 15,000 shares were sold at prices between $15.00 and $15.12. The weighted average sale price was $15.0256 per share, and the insider has committed to provide detailed breakdowns of each individual transaction price upon request.