GROUP ONE TRADING LLC

Position in NPKI — NPK International Inc.

CIK 932540 CHICAGO, IL

Position in NPKI

as of Jun 30, 2026 · filed Aug 14, 2026 Compact

Position Value

$23,355

+$8,967 QoQ

Shares Held

1,468

+47.8% QoQ

Ownership

0.002%

of shares outstanding

% of Portfolio

0.00%

of 13F equity value

Holder Rank

#215

of 256 holders

Holding Since

Mar 2020

12 quarters on record

Voting authority Sole 100% Shared 0% None 0%

Industrials · as of Jun 30, 2026

GROUP ONE TRADING LLC holds $5,585,908 across 10 Building Products & Equipment names. NPKI ranks #7 (0.4% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	BLDR	Builders FirstSource, Inc.	23,094	$2,066,451
2	TT	Trane Technologies plc	2,721	$1,336,446
3	WMS	Advanced Drainage Systems, Inc.	7,240	$1,136,390
4	FBIN	Fortune Brands Innovations, Inc.	10,627	$583,422
5	LMB	Limbach Holdings, Inc.	4,930	$379,610
6	SPXC	SPX Technologies, Inc.	131	$32,117
7	NPKI	NPK International Inc. This page	1,468	$23,355
8	LPX	Louisiana-Pacific Corp	199	$15,653

12 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-06-30	$23,355	1,468	+47.8%	Shares	Sole	2026-08-14
2026-03-31	$14,388	993	-71.5%	Shares	Sole	2026-05-13
2025-12-31	$41,529	3,484	-65.8%	Shares	Sole	2026-02-12
2024-06-30	$84,687	10,191	-28.8%	Shares	Sole	2024-08-14
2023-12-31	$95,018	14,310	+362.7%	Shares	Sole	2024-02-14
2022-12-31	$12,835	3,093	0.0%	Shares	Sole	2023-02-09
2022-09-30	$7,794	3,093	+2521.2%	Shares	Sole	2022-11-09
2022-03-31	$431	118	-92.4%	Shares	Sole	2022-05-12
2020-12-31	$2,989	1,557	0.0%	Shares	Sole	2021-02-10
2020-09-30	$1,634	1,557	0.0%	Shares	Sole	2020-11-12
2020-06-30	$3,472	1,557	0.0%	Shares	Sole	2020-08-13
2020-03-31	$1,401	1,557	—	Shares	Sole	2020-05-13
No filing history on record for this holder in this stock.