Columbia Symbol COLB Positions for Major 2026 Catalyst: What Investors Need to Know Post-Merger

Columbia Banking System’s (COLB) integration of Pacific Premier is hitting its stride heading into 2026, and the numbers suggest the merger could unlock significant value. After completing the acquisition in late August 2025, Columbia symbol COLB now operates roughly 350 branches across eight Western states—a scale shift that changes the competitive equation in the region.

The Balance Sheet Math: Where Columbia Banking System Stands

By September 30, 2025, COLB had assembled an impressive balance sheet: $55.8 billion in deposits, $48.5 billion in loans and leases, and $67.5 billion in total assets. The deposit base is particularly noteworthy—heavily skewed toward non-interest and money market categories, which provides stickiness in a volatile rate environment. This relationship-focused deposit mix is core to Columbia Banking System’s defensive positioning as rates drift lower through 2026.

Margin Resilience in a Falling Rate World

Here’s the critical part: COLB’s net interest margin actually expanded to 3.84% in the third quarter of 2025, up from 3.56% a year earlier. That’s counterintuitive when rates are falling, but it reflects disciplined deposit repricing and a shift away from expensive wholesale funding.

Management guided to roughly 3.90% NIM for Q4 2025 and Q1 2026, with a temporary boost from deposit-premium amortization adding roughly $12 million in Q4—essentially 8 basis points to the margin line. The strategy is clear: defend core net interest income while the portfolio remix unfolds. Even as earning assets tick slightly lower, the composition shift preserves profitability.

Fee Income Gets a Turbocharged Engine

Columbia Banking System isn’t relying on margin expansion alone. The company’s wealth management, trust services, treasury management, and commercial card businesses are accelerating. Treasury management, commercial card, wealth and trust combined now represent nearly 30% of non-interest income as of late September 2025.

Pacific Premier brought new platforms to the table—Custodial Trust Services, HOA banking, escrow, and 1031 exchanges—plus over 1,200 cross-sell referrals since the merger closed. These aren’t incremental; they’re structural revenue streams that should make Columbia symbol COLB’s earnings more resilient as NIM pressures inevitably arrive.

The Cost Takeout Timeline Gets Real

Cost synergies are the merger’s backbone. Management is targeting $127 million in annualized savings, and $48 million has already materialized by end of September. Operating expenses (excluding customer-directed investments) are expected to run $330–$340 million per quarter for the next several quarters.

Full system conversion is slated for Q1 2026, with normalized expense run rates expected by Q3 2026. That means peak integration costs are already baked into current guidance—a bullish signal for earnings power later in the year.

Capital Deployment: Offense and Defense Both on the Table

COLB’s capital ratios improved through 2025. The CET1 ratio stands at 11.6% and total risk-based at 13.4%—both above long-term targets. The board authorized $700 million in share repurchases through November 2026 and raised the quarterly dividend 3% to 37 cents per share.

Tangible book dilution from the deal was just 1.7%, with earn-back reduced to under a year. That math leaves room to deploy excess capital through buybacks while integration benefits accrue, supporting EPS accretion without sacrificing balance sheet strength.

2026 Earnings Outlook and the Key Execution Risk

Street consensus clusters around low-$3 earnings per share for 2026, with a modest step-up expected in 2027 as cost synergies and portfolio remix flow through. Management is targeting high-teens operating ROTCE, assuming a stable macroeconomic backdrop.

Execution hinges on remix timing—shifting away from transactional multi-family lending toward relationship commercial real estate and owner-occupied properties where pipelines improved in Q3. Loan growth should remain muted near-term as runoff offsets new originations, but the quality shift matters more than volume here.

Watch for three near-term headwinds: integration costs keeping expenses volatile, elevated FinPac lease losses that spiked charge-offs in Q3, and aggressive deposit pricing from larger competitors. COLB’s office exposure stands at 8% of loans, and non-performing assets moved to nearly $200 million from $168 million year-over-year—not alarming but worth monitoring as credit cycles age.

Why 2026 Is the Inflection Year

Columbia Banking System trades on the success of integration and its ability to defend deposit franchises while cost saves accelerate. The merger transforms COLB from a mid-sized regional player into a meaningful Western competitor with scale, fee diversification, and a clearer earnings trajectory. The pieces are in place; execution now matters most heading into 2026.