SYSTEM1 INC

Ticker: SST CUSIP: 87200P208 Class: Common Stock

GROUP ONE TRADING, L.P.'s Holding History (CIK: 0000932540)

Note: Option positions (PUT/CALL) are excluded.

Q4 2025

Shares 663 Value ($000) $3 Avg Close $5.17 Range $3.08 - $9.30

Q3 2025

Shares 721 Value ($000) $5 Avg Close $6.91 Range $4.95 - $9.27

Q2 2025

Shares 2,074 Value ($000) $11 Avg Close $4.44 Range $2.90 - $15.00

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2025	663	$3	$5.17	$3.08 - $9.30
Q3 2025	721	$5	$6.91	$4.95 - $9.27
Q2 2025	2,074	$11	$4.44	$2.90 - $15.00