As of August 2026 First Interstate BancSystem has a market cap of โน339.46 Billion. This makes First Interstate BancSystem the world's 3927th 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 Aug 10th, 2026 the market cap of First Interstate BancSystem was reported to be: