As of September 09, 2026, NPK International's top three insider holders are Gregg Piontek (Senior Vice President And Cfo, 858.18K shares), David A Paterson (Vp President, Fluids Systems, 386.25K shares), David A Paterson (Vp President, Fluids Systems, 386.25K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Gregg Piontek | Senior Vice President And Cfo | 858,182 | 0 | 858,182 | 21.9% | 03 Jun, 2026 |
| 2 | David A Paterson | Vp President, Fluids Systems | 386,245 | 0 | 386,245 | 9.9% | 04 Jun, 2024 |
| 3 | Donald Win Young | Director | 310,940 | 0 | 310,940 | 7.9% | 19 May, 2025 |
| 4 | Douglas L White | Vp, Cao Treasurer | 305,245 | 0 | 305,245 | 7.8% | 17 Jun, 2025 |
| 5 | Mary Celeste Fruge | Vp, General Counsel | 284,641 | 0 | 284,641 | 7.3% | 03 Jun, 2026 |
| 6 | Matthew Lanigan | President Ceo | 254,699 | 0 | 254,699 | 6.5% | 05 Jun, 2026 |
| 7 | John C Minge | Director | 253,942 | 0 | 253,942 | 6.5% | 21 May, 2026 |
| 8 | Lori Briggs | Vp President, Ind. Solutions | 247,165 | 0 | 247,165 | 6.3% | 09 Jun, 2026 |
| 9 | Anthony James Best | Director | 237,809 | 0 | 237,809 | 6.1% | 20 May, 2022 |
| 10 | Edward Chipman Earle | Vp, General Counsel, Cao | 230,265 | 0 | 230,265 | 5.9% | 16 Dec, 2022 |
| 11 | Rose M Robeson | Director | 215,147 | 0 | 215,147 | 5.5% | 31 Aug, 2026 |
| 12 | Michael A Lewis | Director | 135,865 | 0 | 135,865 | 3.5% | 19 Aug, 2026 |
| 13 | Claudia Michel Meer | Director | 126,693 | 0 | 126,693 | 3.2% | 21 May, 2026 |
| 14 | Joseph A Cutillo | Director | 36,155 | 0 | 36,155 | 0.9% | 21 May, 2026 |
| 15 | Roderick A. Larson | Director | 23,655 | 0 | 23,655 | 0.6% | 21 May, 2026 |
| 16 | Kristen J. Pederson | Director | 6,614 | 0 | 6,614 | 0.2% | 29 Jul, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 27 Aug, 2026 | Rose M Robeson | Director | Disposed S | 10,000 | $13.49 | $134.92K | 215,147 | Direct |
| 17 Aug, 2026 | Michael A Lewis | Director | Disposed S | 2,013 | $14.26 | $28.71K | 135,865 | Direct |
| 28 Jul, 2026 | Kristen J. Pederson | Director | Acquired A | 6,614 | $0.00 | $0 | 6,614 | Direct |
| 28 Jul, 2026 | Kristen J. Pederson | Director | Acquired A | 6,614 | $0.00 | $0 | 6,614 | Direct |
| 08 Jun, 2026 | Lori Briggs | Vp President, Ind. Solutions | Disposed S | 8,325 | $14.75 | $122.79K | 247,165 | Direct |
| 03 Jun, 2026 | Matthew Lanigan | President Ceo | Disposed S | 167,375 | $14.43 | $2.42Mn | 254,699 | Direct |
| 01 Jun, 2026 | Gregg Piontek | Senior Vice President And Cfo | Disposed F | 8,959 | $14.31 | $128.20K | 844,933 | Direct |
| 01 Jun, 2026 | Mary Celeste Fruge | Vp, General Counsel | Disposed F | 3,833 | $14.31 | $54.85K | 279,382 | Direct |
| 01 Jun, 2026 | Lori Briggs | Vp President, Ind. Solutions | Disposed F | 5,401 | $14.31 | $77.29K | 257,950 | Direct |
| 01 Jun, 2026 | Matthew Lanigan | President Ceo | Disposed F | 22,232 | $14.31 | $318.14K | 389,203 | Direct |
| 01 Jun, 2026 | Gregg Piontek | Senior Vice President And Cfo | Disposed F | 15,889 | $14.31 | $227.37K | 829,044 | Direct |
| 01 Jun, 2026 | Lori Briggs | Vp President, Ind. Solutions | Disposed F | 9,577 | $14.31 | $137.05K | 248,373 | Direct |
| 01 Jun, 2026 | Matthew Lanigan | President Ceo | Disposed F | 27,894 | $14.31 | $399.16K | 361,309 | Direct |
| 01 Jun, 2026 | Mary Celeste Fruge | Vp, General Counsel | Disposed F | 5,218 | $14.31 | $74.67K | 274,164 | Direct |
| 01 Jun, 2026 | Matthew Lanigan | President Ceo | Disposed F | 39,423 | $14.31 | $564.14K | 321,886 | Direct |
| 01 Jun, 2026 | Lori Briggs | Vp President, Ind. Solutions | Disposed F | 6,777 | $14.31 | $96.98K | 241,596 | Direct |
| 01 Jun, 2026 | Mary Celeste Fruge | Vp, General Counsel | Disposed F | 6,797 | $14.31 | $97.27K | 267,367 | Direct |
| 01 Jun, 2026 | Gregg Piontek | Senior Vice President And Cfo | Disposed F | 11,241 | $14.31 | $160.86K | 817,803 | Direct |
| 01 Jun, 2026 | Matthew Lanigan | President Ceo | Acquired M | 100,188 | $0.00 | $0 | 422,074 | Direct |
| 01 Jun, 2026 | Lori Briggs | Vp President, Ind. Solutions | Acquired M | 24,340 | $0.00 | $0 | 265,936 | Direct |