As of September 2026 First Interstate BancSystem has a market cap of โน341.23 Billion. This makes First Interstate BancSystem the world's 3852th 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 Sep 19th, 2026 the market cap of First Interstate BancSystem was reported to be: