FIRST INTST BANCSYSTEM INC

Ticker: FIBK CUSIP: 32055Y201 Class: Common Stock

Optiver Holding B.V.'s Holding History (CIK: 0001859606)

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

Q4 2025

Shares 179 Value ($000) $6 Avg Close $32.13 Range $28.33 - $35.91

Q2 2025

Shares 283 Value ($000) $8 Avg Close $25.62 Range $21.60 - $28.14

Q1 2025

Shares 241 Value ($000) $7 Avg Close $28.99 Range $25.84 - $31.59

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2025	179	$6	$32.13	$28.33 - $35.91
Q2 2025	283	$8	$25.62	$21.60 - $28.14
Q1 2025	241	$7	$28.99	$25.84 - $31.59