SIMPLEX TRADING, LLC

Position in MSB — Mesabi Trust

CIK 1488542 CHICAGO, IL

Position in MSB

as of Mar 31, 2026 · filed May 14, 2026 Compact

Position Value

$78,214

+$77,663 QoQ

Shares Held

2,483

+10695.7% QoQ

Ownership

0.019%

of shares outstanding

% of Portfolio

0.00%

of 13F equity value

Holder Rank

—

not a current holder

Holding Since

Mar 2020

16 quarters on record

Voting authority Sole 100% Shared 0% None 0%

Basic Materials · as of Mar 31, 2026

SIMPLEX TRADING, LLC holds $1,369,956 across 9 Steel names. MSB ranks #4 (5.7% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	ASTL	Algoma Steel Group Inc.	154,905	$639,757
2	RS	Reliance, Inc.	819	$248,910
3	TX	Ternium S.A.	4,790	$192,318
4	MSB	Mesabi Trust This page	2,483	$78,214
5	MTUS	Metallus Inc.	4,169	$68,121
6	SID	National Steel Co	44,613	$55,320
7	PKX	Posco Holdings Inc.	608	$35,561
8	GGB	Gerdau S.A.	9,302	$33,580

16 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-03-31	$78,214	2,483	+10695.7%	Shares	Sole	2026-05-14
2025-06-30	$551	23	-96.4%	Shares	Sole	2025-08-05
2025-03-31	$17,516	644	+10633.3%	Shares	Sole	2025-05-12
2023-12-31	$122	6	-92.8%	Shares	Sole	2024-02-02
2023-09-30	$1,665	83	-85.8%	Shares	Sole	2023-11-01
2023-06-30	$11,899	583	+58.4%	Shares	Sole	2023-08-04
2023-03-31	$9,266	368	-92.1%	Shares	Sole	2023-04-27
2022-12-31	$84,459	4,687	-22.7%	Shares	Sole	2023-02-02
2022-09-30	$130,436	6,064	+3787.2%	Shares	Sole	2022-11-04
2022-06-30	$3,825	156	-90.5%	Shares	Sole	2022-08-03
2022-03-31	$43,662	1,639	-83.0%	Shares	Sole	2022-05-02
2021-12-31	$254,133	9,619	+437.1%	Shares	Sole	2022-02-23
2021-09-30	$53,210	1,791	0.0%	Shares	Sole	2021-10-28
2021-06-30	$63,401	1,791	-78.2%	Shares	Sole	2021-08-12
2021-03-31	$247,197	8,218	+211.1%	Shares	Sole	2021-04-26
2020-03-31	$37,780	2,642	—	Shares	Sole	2020-04-29
No filing history on record for this holder in this stock.