Columbia Banking System(COLB) - 2025 Q2 - Quarterly Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the quarterly period ended: June 30, 2025 or ☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to . Commission File Number: 000-20288 COLUMBIA BANKING SYSTEM, INC. (State or Other Jurisdiction (I.R.S. Employer Identification Number) of Incorporation or Organizatio ...