COLB ▼ -0.1% - Columbia Banking System, Inc. $COLB - KBRA Assigns Rating to $250 Million Subordinated Notes Issued by Columbia Bank Columbia Banking System fell 0.1% today after KBRA assigned a rating to the company's $250 million subordinated notes offering. The modest decline suggests the market absorbed the debt issuance and credit rating with limited reaction, as subordinated debt financings are routine capital management activities for regional banks. 18-SEP-2026 04:16 PM ET