Gregg S. Piontek - 04 Mar 2026 Form 4 Insider Report for NPK International Inc. (NPKI)

Reporting relationship: Senior Vice President and CFO
Issuer ticker: NPKI
Reported as of: 04 Mar 2026
Net transaction value: -$1,528,056
SEC form: 4
Accepted by SEC: 05 Mar 2026, 17:50:16 UTC
Prior SEC filing: 03 Jun 2025
Next SEC filing: 26 Mar 2026
Source filing: View source filing
Reporting owner signature: By: M. Celeste Fruge For: Gregg S. Piontek

Key filing fact

Gregg S. Piontek filed Form 4 for NPK International Inc. (NPKI) on 05 Mar 2026.

Key facts

This page summarizes Gregg S. Piontek's Form 4 filing for NPK International Inc. (NPKI).
4 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 05 Mar 2026, 17:50.

Change

Previous filing in this sequence was filed on 03 Jun 2025.
Current net transaction value: -$1,528,056.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001418328 Primary reporting owner

Piontek Gregg

Relationship: Senior Vice President and CFO
Address: 9320 LAKESIDE BOULEVARD, SUITE 100, THE WOODLANDS
Signature: By: M. Celeste Fruge For: Gregg S. Piontek
Signature date: 05 Mar 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

NPKI transaction

Common Stock

Options Exercise

Transaction value
Shares: +73,590
Change %: +8%
Price: $4.32^*
Shares after: 992,916
Date: 04 Mar 2026
Ownership: Direct
Footnotes: F1

NPKI transaction

Common Stock

Sale

Transaction value: $1,037,464
Shares: -73,590
Change %: -7.4%
Price: $14.10
Shares after: 919,326
Date: 04 Mar 2026
Ownership: Direct
Footnotes: F1, F2

NPKI transaction

Common Stock

Sale

Transaction value: $490,592
Shares: -35,000
Change %: -3.8%
Price: $14.02
Shares after: 884,326
Date: 04 Mar 2026
Ownership: Direct
Footnotes: F3, F4

NPKI holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 65,000
Date: 04 Mar 2026
Ownership: by IRA
Footnotes: F5

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

NPKI transaction Derivative

Non-Qualified Stock Option (right to buy)

Options Exercise

Transaction value
Shares: -73,590
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 04 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 73,590
Exercise price: $4.32
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 5 footnotes

Footnote F1

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.

Footnote F2

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.

Footnote F3

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.

Footnote F4

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.

Footnote F5

These shares are indirectly held by Trust.