NPK International Inc. (NPKI)

Data as of Sep 24, 2026, from SEC Form 4 filings.

Net insider selling (90d)Watch NPKI

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Latest NPKI insider trades

Matthew James Warren - Officer
Open-market sale$40K
Sep 9, 2026
Rose M. Robeson - Director
Open-market sale$135K

About NPK International Inc. (NPKI)

NPK International Inc. files with the SEC under CIK 0000071829 and is classified as miscellaneous equipment rental and leasing. We track it alongside the rest of the Industrials sector.

Sector: Industrials

SEC filings for NPKI on EDGAR

NPKI Form 4 activity by transaction type, last 90 days

Form 4 transaction type	Transactions	Shares	Total value
Open-market sale	3	15,004	$204K
Grant or award	2	19,464

Dollar totals cover purchases and sales only (codes P and S). Grants, option exercises, gifts and tax withholding are counted in shares, because none of them is a trade at a market price.

NPKI insider transactions (Form 4)

40 Form 4 filings on record, the earliest from Dec 17, 2024, newest first. Filing history page 1 of 2.

Date	Insider	Transaction	Security	Shares	Price	Value
Sep 22, 2026	Iii Alvin James Barton - Officer	Grant or award	Common Stock	12,850^{footnote F1}	$0.00	-
Footnote F1 (shares): Grant of restricted stock units that vests one-half on the second anniversary of the date of grant and remaining one-half on the fourth anniversary of the date of grant and settles in shares.
Sep 9, 2026	Matthew James Warren - Officer	Open-market sale	Common Stock	2,991^{footnote F1}	$13.41^{footnote F2}	$40K
Footnote F1 (shares): The reported sale of 2,991 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 17, 2025. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.33 to $13.51, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Aug 27, 2026	Rose M. Robeson - Director	Open-market sale	Common Stock	10,000^{footnote F1}	$13.49^{footnote F2}	$135K
Footnote F1 (shares): The reported sale of 10,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 27, 2026. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.11 to $13.72, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Aug 17, 2026	Michael A. Lewis - Director	Open-market sale	Common Stock	2,013^{footnote F1}	$14.26^{footnote F2}	$29K
Footnote F1 (shares): The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.15 to $14.40, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Jul 28, 2026	Kristen J. Pederson - Director	Grant or award	Common Stock	6,614^{footnote F1}	$0.00	-
Footnote F1 (shares): Represents pro-rated portion of non-employee director's annual equity retainer. The shares will vest on the earlier of the first anniversary of the date of grant or the day priopr to the next annual stockholders meeting.
Jun 8, 2026	Lori Briggs - Officer	Open-market sale	Common Stock	8,325^{footnote F1}	$14.75^{footnote F2}	$123K
Footnote F1 (shares): The reported sale of 8,325 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.40 to $15.03, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Jun 3, 2026	Matthew Lanigan - Officer	Open-market sale	Common Stock	167,375^{footnote F1}	$14.43^{footnote F2}	$2.42M
Footnote F1 (shares): The reported sale of 167,375 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 4, 2026. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.29 to $14.56, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Jun 1, 2026	Mary Celeste Fruge - Officer	Tax withholding / forfeiture	Common Stock	3,833^{footnote F1}	$14.31	$55K
Jun 1, 2026	Mary Celeste Fruge - Officer	Tax withholding / forfeiture	Common Stock	5,218^{footnote F1}	$14.31	$75K
Jun 1, 2026	Mary Celeste Fruge - Officer	Tax withholding / forfeiture	Common Stock	6,797^{footnote F1}	$14.31	$97K
Jun 1, 2026	Mary Celeste Fruge - Officer	Option exercise	Common Stock	17,274	$0.00^{footnote F2}	-
Jun 1, 2026	Mary Celeste Fruge - Officer	Option exercise	Restricted Stock Units	17,274	$0.00	-
Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units. Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.
Jun 1, 2026	Matthew Lanigan - Officer	Tax withholding / forfeiture	Common Stock	22,232^{footnote F1}	$14.31	$318K
Jun 1, 2026	Matthew Lanigan - Officer	Tax withholding / forfeiture	Common Stock	27,894^{footnote F1}	$14.31	$399K
Jun 1, 2026	Matthew Lanigan - Officer	Tax withholding / forfeiture	Common Stock	39,423^{footnote F1}	$14.31	$564K
Jun 1, 2026	Matthew Lanigan - Officer	Option exercise	Common Stock	100,188	$0.00^{footnote F2}	-
Jun 1, 2026	Matthew Lanigan - Officer	Option exercise	Restricted Stock Units	100,188	$0.00	-
Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units. Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.
Jun 1, 2026	Gregg Piontek - Officer	Tax withholding / forfeiture	Common Stock	8,959^{footnote F1}	$14.31	$128K
Jun 1, 2026	Gregg Piontek - Officer	Tax withholding / forfeiture	Common Stock	15,889^{footnote F1}	$14.31	$227K
Jun 1, 2026	Gregg Piontek - Officer	Tax withholding / forfeiture	Common Stock	11,241^{footnote F1}	$14.31	$161K
Jun 1, 2026	Gregg Piontek - Officer	Option exercise	Common Stock	40,379	$0.00^{footnote F2}	-
Jun 1, 2026	Gregg Piontek - Officer	Option exercise	Restricted Stock Units	40,379	$0.00	-
Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units. Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.
Jun 1, 2026	Lori Briggs - Officer	Tax withholding / forfeiture	Common Stock	5,401^{footnote F1}	$14.31	$77K
Jun 1, 2026	Lori Briggs - Officer	Tax withholding / forfeiture	Common Stock	9,577^{footnote F1}	$14.31	$137K
Jun 1, 2026	Lori Briggs - Officer	Tax withholding / forfeiture	Common Stock	6,777^{footnote F1}	$14.31	$97K
Jun 1, 2026	Lori Briggs - Officer	Option exercise	Common Stock	24,340	$0.00^{footnote F2}	-
Jun 2, 2026	Lori Briggs - Officer	Open-market sale	Common Stock	10,446^{footnote F3}	$14.58^{footnote F4}	$152K
Jun 1, 2026	Lori Briggs - Officer	Option exercise	Restricted Stock Units	24,340	$0.00	-
Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units. Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis. Footnote F3 (shares): The reported sale of 10,446 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025. Footnote F4 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.74, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
May 20, 2026	Rose M. Robeson - Director	Grant or award	Common Stock	10,862^{footnote F1}	$0.00	-
Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.
May 20, 2026	John C. Minge - Director	Grant or award	Common Stock	8,558^{footnote F1}	$0.00	-
Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.
May 20, 2026	Claudia Michel Meer - Director	Grant or award	Common Stock	8,558^{footnote F1}	$0.00	-
Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.
May 20, 2026	Michael A. Lewis - Director	Grant or award	Common Stock	8,558^{footnote F1}	$0.00	-
Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.
May 20, 2026	Roderick A. Larson - Director	Grant or award	Common Stock	8,558^{footnote F1}	$0.00	-
Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.
May 20, 2026	Joseph A. Cutillo - Director	Grant or award	Common Stock	8,558^{footnote F1}	$0.00	-
Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.
May 19, 2026	Gregg Piontek - Officer	Grant or award	Common Stock	34,566^{footnote F1}	$0.00	-
Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.
May 19, 2026	Matthew Lanigan - Officer	Grant or award	Common Stock	85,771^{footnote F1}	$0.00	-
Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.
May 19, 2026	Mary Celeste Fruge - Officer	Grant or award	Common Stock	18,002^{footnote F1}	$0.00	-
Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.
May 19, 2026	Lori Briggs - Officer	Grant or award	Common Stock	20,838^{footnote F1}	$0.00	-
Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.
May 15, 2026	Michael A. Lewis - Director	Open-market sale	Common Stock	2,013^{footnote F1}	$15.30^{footnote F2}	$31K
Footnote F1 (shares): The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $15.21 to $15.54, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Apr 9, 2026	Gregg Piontek - Officer	Open-market sale	Common Stock	15,000^{footnote F1}	$15.05^{footnote F2}	$226K
Footnote F1 (shares): 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. Footnote F2 (price): 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 $15.10, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Apr 1, 2026	Gregg Piontek - Officer	Open-market sale	Common Stock	35,000^{footnote F1}	$14.51^{footnote F2}	$508K
Footnote F1 (shares): 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 F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.68, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Mar 25, 2026	Gregg Piontek - Officer	Open-market sale	Common Stock	15,000^{footnote F1}	$15.03^{footnote F2}	$225K
Footnote F1 (shares): 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. Footnote F2 (price): 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… Full note on SEC EDGAR
Mar 16, 2026	Mary Celeste Fruge - Officer	Option exercise	Common Stock	1,000^{footnote F1}	$4.32	$4K
Mar 16, 2026	Mary Celeste Fruge - Officer	Open-market sale	Common Stock	1,000^{footnote F1}	$13.56^{footnote F2}	$14K
Mar 16, 2026	Mary Celeste Fruge - Officer	Option exercise	Non-Qualified Stock Option (right to buy)	1,000^{footnote F1}	$0.00	-
Footnote F1 (shares): The reported exercise of 1,000 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 5, 2025. Footnote F2 (price): These options were sold on the open market at price stated. 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… Full note on SEC EDGAR
Mar 6, 2026	Mary Celeste Fruge - Officer	Open-market sale	Common Stock	11,193^{footnote F1}	$13.34^{footnote F2}	$149K
Mar 6, 2026	Mary Celeste Fruge - Officer	Option exercise	Non-Qualified Stock Option (right to buy)	11,193^{footnote F1}	$0.00	-
Mar 6, 2026	Mary Celeste Fruge - Officer	Option exercise	Common Stock	11,193^{footnote F1}	$4.32	$48K
Footnote F1 (shares): The reported exercise of 11,193 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 5, 2025. Footnote F2 (price): The price reported is the weighted average price. These options were sold in multiple transactions in the open market at prices ranging from $13.24 to $13.48, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK… Full note on SEC EDGAR
Mar 4, 2026	Gregg Piontek - Officer	Option exercise	Non-Qualified Stock Option (right to buy)	73,590^{footnote F1}	$0.00	-
Mar 4, 2026	Gregg Piontek - Officer	Option exercise	Common Stock	73,590^{footnote F1}	$4.32	$318K
Mar 4, 2026	Gregg Piontek - Officer	Open-market sale	Common Stock	73,590^{footnote F1}	$14.10^{footnote F2}	$1.04M
Mar 4, 2026	Gregg Piontek - Officer	Open-market sale	Common Stock	35,000^{footnote F3}	$14.02^{footnote F4}	$491K
Footnote F1 (shares): 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 (price): 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… Full note on SEC EDGAR Footnote F3 (shares): 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 (price): 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… Full note on SEC EDGAR
Feb 23, 2026	Michael A. Lewis - Director	Open-market sale	Common Stock	2,013^{footnote F1}	$14.31^{footnote F2}	$29K
Footnote F1 (shares): The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025. Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.11 to $14.43, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR
Jun 1, 2025	Mary Celeste Fruge - Officer	Option exercise	Common Stock	17,274	$0.00	-
Jun 1, 2025	Mary Celeste Fruge - Officer	Option exercise	Restricted Stock Units	17,274	$0.00	-

Recent NPKI Form 8-K filings

Read NPKI company news

Sep 14, 2026Item 5.02, 9.01

Read the filing on SEC EDGAR

Sep 2, 2026Item 5.02, 9.01

Read the filing on SEC EDGAR

Jul 30, 2026Item 7.01, 9.01

Read the filing on SEC EDGAR

Jul 29, 2026Item 2.02, 9.01

Read the filing on SEC EDGAR

Recent NPKI Form 144 notices of proposed sale

An insider files Form 144 before selling restricted or control stock. It announces a planned sale. If the sale goes ahead, it shows up later on a Form 4.

Filed	Filer	Relationship	Shares	Market value	Notice
Sep 9, 2026	MATTHEW WARREN	Officer	2,991	$40K	View on EDGAR
Aug 27, 2026	ROBESON ROSE M	Director	10,000	$135K

NPKI insider trading FAQ

What is the latest insider trade for NPKI?

NPK International Inc. (NPKI) had 5 insider filings in the last 90 days, with the most recent on 2026-09-24. The full record for NPKI runs to 40 Form 4 filings, the earliest from 2024-12-17. InsiderAlpha adds new Form 4, Form 144 and 8-K filings as they arrive from SEC EDGAR.

How many insiders are buying NPKI stock?

No insider purchases of NPKI were filed in the last 90 days.

How many insiders are selling NPKI stock?

3 insider sales of NPKI were filed in the last 90 days, totaling $204K.

Where can I see NPKI SEC filings (Form 4, 10-K, 10-Q, 8-K)?

This page collects NPKI Form 4 insider transactions, Form 144 sale notices and 8-K filings in one place. Annual 10-K and quarterly 10-Q reports live on the company's SEC EDGAR page.

More Industrials companies with insider activity

Recent insider filings

The EDGAR links open each original Form 4, so you can check any number on this page against the filing it came from.

Sep 24, 2026 - Iii Alvin James Barton view on EDGAR
Sep 10, 2026 - Matthew James Warren view on EDGAR
Aug 31, 2026 - Rose M. Robeson view on EDGAR
Aug 19, 2026 - Michael A. Lewis view on EDGAR
Jul 29, 2026 - Kristen J. Pederson view on EDGAR
Jun 9, 2026 - Lori Briggs view on EDGAR
Jun 5, 2026 - Matthew Lanigan view on EDGAR
Jun 3, 2026 - Mary Celeste Fruge view on EDGAR
Jun 3, 2026 - Matthew Lanigan view on EDGAR

Related companies with recent insider activity

Learn more

Insider selling: signal or noise?: Why most insider sales are routine, and the few patterns worth a second look.
Form 144 vs Form 4: A Form 144 announces a planned sale; the Form 4 reports it after it happens.
Insider activity in Industrials: Where NPKI's peers are being bought and sold.
Every recent Form 4: The market-wide feed, updated as filings arrive from SEC EDGAR.

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Form 4 transaction type

Transactions

Total value

Open-market sale

15,004

$204K

Grant or award

19,464

Date

Insider

Transaction

Security

Price

Value

Sep 22, 2026

Iii Alvin James Barton - Officer

Grant or award

Common Stock

12,850^{footnote F1}

$0.00

Footnote F1 (shares): Grant of restricted stock units that vests one-half on the second anniversary of the date of grant and remaining one-half on the fourth anniversary of the date of grant and settles in shares.

Sep 9, 2026

Matthew James Warren - Officer

Open-market sale

Common Stock

2,991^{footnote F1}

$13.41^{footnote F2}

$40K

Footnote F1 (shares): The reported sale of 2,991 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 17, 2025.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.33 to $13.51, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Aug 27, 2026

Rose M. Robeson - Director

Open-market sale

Common Stock

10,000^{footnote F1}

$13.49^{footnote F2}

$135K

Footnote F1 (shares): The reported sale of 10,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 27, 2026.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.11 to $13.72, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Aug 17, 2026

Michael A. Lewis - Director

Open-market sale

Common Stock

2,013^{footnote F1}

$14.26^{footnote F2}

$29K

Footnote F1 (shares): The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.15 to $14.40, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Jul 28, 2026

Kristen J. Pederson - Director

Grant or award

Common Stock

6,614^{footnote F1}

$0.00

Footnote F1 (shares): Represents pro-rated portion of non-employee director's annual equity retainer. The shares will vest on the earlier of the first anniversary of the date of grant or the day priopr to the next annual stockholders meeting.

Jun 8, 2026

Lori Briggs - Officer

Open-market sale

Common Stock

8,325^{footnote F1}

$14.75^{footnote F2}

$123K

Footnote F1 (shares): The reported sale of 8,325 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.40 to $15.03, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Jun 3, 2026

Matthew Lanigan - Officer

Open-market sale

Common Stock

167,375^{footnote F1}

$14.43^{footnote F2}

$2.42M

Footnote F1 (shares): The reported sale of 167,375 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 4, 2026.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.29 to $14.56, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Jun 1, 2026

Mary Celeste Fruge - Officer

Tax withholding / forfeiture

Common Stock

3,833^{footnote F1}

$14.31

$55K

Jun 1, 2026

Mary Celeste Fruge - Officer

Tax withholding / forfeiture

Common Stock

5,218^{footnote F1}

$14.31

$75K

Jun 1, 2026

Mary Celeste Fruge - Officer

Tax withholding / forfeiture

Common Stock

6,797^{footnote F1}

$14.31

$97K

Jun 1, 2026

Mary Celeste Fruge - Officer

Option exercise

Common Stock

17,274

$0.00^{footnote F2}

Jun 1, 2026

Mary Celeste Fruge - Officer

Option exercise

Restricted Stock Units

17,274

$0.00

Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.
Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.

Jun 1, 2026

Matthew Lanigan - Officer

Tax withholding / forfeiture

Common Stock

22,232^{footnote F1}

$14.31

$318K

Jun 1, 2026

Matthew Lanigan - Officer

Tax withholding / forfeiture

Common Stock

27,894^{footnote F1}

$14.31

$399K

Jun 1, 2026

Matthew Lanigan - Officer

Tax withholding / forfeiture

Common Stock

39,423^{footnote F1}

$14.31

$564K

Jun 1, 2026

Matthew Lanigan - Officer

Option exercise

Common Stock

100,188

$0.00^{footnote F2}

Jun 1, 2026

Matthew Lanigan - Officer

Option exercise

Restricted Stock Units

100,188

$0.00

Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.
Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.

Jun 1, 2026

Gregg Piontek - Officer

Tax withholding / forfeiture

Common Stock

8,959^{footnote F1}

$14.31

$128K

Jun 1, 2026

Gregg Piontek - Officer

Tax withholding / forfeiture

Common Stock

15,889^{footnote F1}

$14.31

$227K

Jun 1, 2026

Gregg Piontek - Officer

Tax withholding / forfeiture

Common Stock

11,241^{footnote F1}

$14.31

$161K

Jun 1, 2026

Gregg Piontek - Officer

Option exercise

Common Stock

40,379

$0.00^{footnote F2}

Jun 1, 2026

Gregg Piontek - Officer

Option exercise

Restricted Stock Units

40,379

$0.00

Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.
Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.

Jun 1, 2026

Lori Briggs - Officer

Tax withholding / forfeiture

Common Stock

5,401^{footnote F1}

$14.31

$77K

Jun 1, 2026

Lori Briggs - Officer

Tax withholding / forfeiture

Common Stock

9,577^{footnote F1}

$14.31

$137K

Jun 1, 2026

Lori Briggs - Officer

Tax withholding / forfeiture

Common Stock

6,777^{footnote F1}

$14.31

$97K

Jun 1, 2026

Lori Briggs - Officer

Option exercise

Common Stock

24,340

$0.00^{footnote F2}

Jun 2, 2026

Lori Briggs - Officer

Open-market sale

Common Stock

10,446^{footnote F3}

$14.58^{footnote F4}

$152K

Jun 1, 2026

Lori Briggs - Officer

Option exercise

Restricted Stock Units

24,340

$0.00

Footnote F1 (shares): Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.
Footnote F2 (price): The restricted stock units vest and convert into shares on a one-for-one basis.
Footnote F3 (shares): The reported sale of 10,446 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025.
Footnote F4 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.74, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

May 20, 2026

Rose M. Robeson - Director

Grant or award

Common Stock

10,862^{footnote F1}

$0.00

Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

May 20, 2026

John C. Minge - Director

Grant or award

Common Stock

8,558^{footnote F1}

$0.00

Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

May 20, 2026

Claudia Michel Meer - Director

Grant or award

Common Stock

8,558^{footnote F1}

$0.00

Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

May 20, 2026

Michael A. Lewis - Director

Grant or award

Common Stock

8,558^{footnote F1}

$0.00

Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

May 20, 2026

Roderick A. Larson - Director

Grant or award

Common Stock

8,558^{footnote F1}

$0.00

Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

May 20, 2026

Joseph A. Cutillo - Director

Grant or award

Common Stock

8,558^{footnote F1}

$0.00

Footnote F1 (shares): The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

May 19, 2026

Gregg Piontek - Officer

Grant or award

Common Stock

34,566^{footnote F1}

$0.00

Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

May 19, 2026

Matthew Lanigan - Officer

Grant or award

Common Stock

85,771^{footnote F1}

$0.00

Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

May 19, 2026

Mary Celeste Fruge - Officer

Grant or award

Common Stock

18,002^{footnote F1}

$0.00

Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

May 19, 2026

Lori Briggs - Officer

Grant or award

Common Stock

20,838^{footnote F1}

$0.00

Footnote F1 (shares): Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

May 15, 2026

Michael A. Lewis - Director

Open-market sale

Common Stock

2,013^{footnote F1}

$15.30^{footnote F2}

$31K

Footnote F1 (shares): The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $15.21 to $15.54, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Apr 9, 2026

Gregg Piontek - Officer

Open-market sale

Common Stock

15,000^{footnote F1}

$15.05^{footnote F2}

$226K

Footnote F1 (shares): 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.
Footnote F2 (price): 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 $15.10, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Apr 1, 2026

Gregg Piontek - Officer

Open-market sale

Common Stock

35,000^{footnote F1}

$14.51^{footnote F2}

$508K

Footnote F1 (shares): 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 F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.68, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Mar 25, 2026

Gregg Piontek - Officer

Open-market sale

Common Stock

15,000^{footnote F1}

$15.03^{footnote F2}

$225K

Footnote F1 (shares): 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.
Footnote F2 (price): 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… Full note on SEC EDGAR

Mar 16, 2026

Mary Celeste Fruge - Officer

Option exercise

Common Stock

1,000^{footnote F1}

$4.32

$4K

Mar 16, 2026

Mary Celeste Fruge - Officer

Open-market sale

Common Stock

1,000^{footnote F1}

$13.56^{footnote F2}

$14K

Mar 16, 2026

Mary Celeste Fruge - Officer

Option exercise

Non-Qualified Stock Option (right to buy)

1,000^{footnote F1}

$0.00

Footnote F1 (shares): The reported exercise of 1,000 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 5, 2025.
Footnote F2 (price): These options were sold on the open market at price stated. 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… Full note on SEC EDGAR

Mar 6, 2026

Mary Celeste Fruge - Officer

Open-market sale

Common Stock

11,193^{footnote F1}

$13.34^{footnote F2}

$149K

Mar 6, 2026

Mary Celeste Fruge - Officer

Option exercise

Non-Qualified Stock Option (right to buy)

11,193^{footnote F1}

$0.00

Mar 6, 2026

Mary Celeste Fruge - Officer

Option exercise

Common Stock

11,193^{footnote F1}

$4.32

$48K

Footnote F1 (shares): The reported exercise of 11,193 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 5, 2025.
Footnote F2 (price): The price reported is the weighted average price. These options were sold in multiple transactions in the open market at prices ranging from $13.24 to $13.48, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK… Full note on SEC EDGAR

Mar 4, 2026

Gregg Piontek - Officer

Option exercise

Non-Qualified Stock Option (right to buy)

73,590^{footnote F1}

$0.00

Mar 4, 2026

Gregg Piontek - Officer

Option exercise

Common Stock

73,590^{footnote F1}

$4.32

$318K

Mar 4, 2026

Gregg Piontek - Officer

Open-market sale

Common Stock

73,590^{footnote F1}

$14.10^{footnote F2}

$1.04M

Mar 4, 2026

Gregg Piontek - Officer

Open-market sale

Common Stock

35,000^{footnote F3}

$14.02^{footnote F4}

$491K

Footnote F1 (shares): 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 (price): 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… Full note on SEC EDGAR
Footnote F3 (shares): 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 (price): 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… Full note on SEC EDGAR

Feb 23, 2026

Michael A. Lewis - Director

Open-market sale

Common Stock

2,013^{footnote F1}

$14.31^{footnote F2}

$29K

Footnote F1 (shares): The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025.
Footnote F2 (price): The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.11 to $14.43, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International… Full note on SEC EDGAR

Jun 1, 2025

Mary Celeste Fruge - Officer

Option exercise

Common Stock

17,274

$0.00

Jun 1, 2025

Mary Celeste Fruge - Officer

Option exercise

Restricted Stock Units

17,274

$0.00

Filed

Filer

Relationship

Market value

Notice

Sep 9, 2026

MATTHEW WARREN

Officer

2,991

$40K

View on EDGAR

Aug 27, 2026

ROBESON ROSE M

Director

10,000

$135K