As of December 2025 First Interstate BancSystem has a market cap of โน333.64 Billion. This makes First Interstate BancSystem the world's 3585th 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 15th, 2025 the market cap of First Interstate BancSystem was reported to be: