As of December 2025 First Interstate BancSystem has a market cap of โน329.73 Billion. This makes First Interstate BancSystem the world's 3602th most valuable company by market cap according to our data. The market capitalization, commonly called market cap, is the total market value of a publicly traded company's outstanding shares and is commonly used to measure how much a company is worth.
On Dec 19th, 2025 the market cap of First Interstate BancSystem was reported to be: