SIMPLEX TRADING, LLC

CIK

1488542

City

CHICAGO

State / Country

IL

Stock

MSB — Mesabi Trust

Top Portfolio Positions

1,972 positions · $2,794,191,358 total · as of Mar 31, 2026

Ticker	Company	Shares	Value (USD)	% of Portfolio	Open
NVDA	Nvidia Corp Technology	1,509,153	$263,196,283	9.42%
AMZN	Amazon Com Inc Consumer Cyclical	764,884	$159,302,390	5.70%
SPY	Spdr S&P 500 ETF Trust	202,806	$131,892,854	4.72%
META	Meta Platforms, Inc. Communication Services	229,853	$131,505,796	4.71%
TSM	Taiwan Semiconductor Manufacturing Co Ltd Technology	351,805	$118,892,499	4.25%
GLD	Spdr Gold Trust	230,612	$99,230,037	3.55%
GOOGL	Alphabet Inc. Communication Services	296,315	$85,208,341	3.05%
UNH	Unitedhealth Group Inc Healthcare	287,580	$77,816,272	2.78%
ORCL	Oracle Corp Technology	514,658	$75,711,338	2.71%
AMD	Advanced Micro Devices Inc Technology	260,622	$53,018,333	1.90%

Portfolio Trend

25 quarters · across all stocks

Holdings in MSB

Compact Export CSV

Shares Held

Position Value (USD)

16 quarters 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 13F history on record for this holder in this stock.