First Interstate Bancsystem Inc.

FIBK·NASDAQ·$36.13Share Price as of 11/2·$4BMarket Cap as of 11/2

Financials

10-QQ2 ended 06/30/2608/03/26 10-QQ1 ended 03/31/2605/07/26 10-KFY 202502/26/26 10-QQ3 ended 09/30/2511/06/25 10-QQ2 ended 06/30/2508/06/25

Disclosures

8-KCurrent report10/22/26 8-KCurrent report09/16/26 8-KCurrent report08/21/26 8-KCurrent report07/23/26 8-KCurrent report07/16/26

Prospectuses and Registrations

S-3ASRAutomatic shelf registration05/26/26 424B5Prospectus supplement06/06/25 424B5Prospectus supplement06/05/25 FWPFree writing prospectus06/05/25 FWPFree writing prospectus06/05/25

Proxies

DEF 14ADefinitive proxy04/16/26 DEFA14AAdditional proxy materials04/16/26 PRE 14APreliminary proxy03/31/26 DEFA14AAdditional proxy materials05/16/25 DEF 14ADefinitive proxy04/08/25

Ownership

144Proposed sale of securities10/30/26 Form 4Insider transaction10/26/26 Form 4Insider transaction10/23/26 144Proposed sale of securities10/22/26 Form 4Insider transaction10/06/26

Other

ARSAnnual report to shareholders04/16/26 305B2305B206/05/25 ARSAnnual report to shareholders04/08/25 ARSAnnual report to shareholders04/11/24 8-A12B/A8-A12B/A05/25/23