Matthew James Warren, Chief Accounting Officer of NPK International Inc. (NYSE:NPKI), filed a Form 4 on September 10, 2026, disclosing the sale of 2,991 shares of common stock on September 9, 2026, pursuant to a pre-established Rule 10b5-1 trading plan.

Key Highlights

  • Shares sold: 2,991 shares of NPK International Inc. common stock were disposed of on September 9, 2026.
  • Weighted average price: $13.4112 per share, with individual transactions ranging from $13.33 to $13.51, inclusive.
  • 10b5-1 plan: The sale occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by Warren on December 17, 2025.
  • Remaining ownership: Following the transaction, Warren directly beneficially owned 51,439 shares of common stock.
  • Reporting person role: Matthew James Warren is identified as Chief Accounting Officer of NPK International Inc.

NPK International CAO Share Sale Details and Plan Background

According to the Form 4 filing, Matthew James Warren, Chief Accounting Officer of NPK International Inc. (NYSE:NPKI), disposed of 2,991 shares of common stock on September 9, 2026. The filing indicates the transaction was coded "S" (a sale) and that the shares were sold directly. The reported weighted average sale price was $13.4112 per share. The filing notes that shares were sold in multiple open-market transactions at prices ranging from $13.33 to $13.51, inclusive.

The filing states that the sale "occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 17, 2025." The form also carries a checkbox indicating the transaction was made pursuant to a contract, instruction, or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). Warren, according to the filing, undertakes to provide full information regarding the number of shares sold at each separate price within the stated range upon request by NPK International Inc., any security holder, or the SEC staff.

Following the reported sale, the filing discloses that Warren directly beneficially owned 51,439 shares of NPK International Inc. common stock. No derivative securities transactions were reported in this filing. The Form 4 was signed on September 10, 2026, by M. Celeste Fruge on behalf of Matthew Warren.

What Was Disclosed

The filing discloses a single open-market sale of 2,991 shares of NPK International common stock by Chief Accounting Officer Matthew James Warren on September 9, 2026, executed under a pre-established 10b5-1 plan, leaving him with 51,439 shares directly held.