Finvest
COLB Regional Banks · Western U.S. · Commercial bank · Capital return · Thesis updated June 14, 2026

Merger cleanup is becoming a buyback story

01 Running thesis

Execution is the story now

Columbia has moved past the biggest Pacific Premier integration worry. The systems conversion finished in Q1 2026, and management still expects all disclosed cost savings from the deal to be in place by June 30, 2026. That matters because the bank is trying to prove the deal can lift earnings without needing a much bigger balance sheet.

The bull case is simple: cut the costs, remix the loan book, lower funding costs, and buy back stock. Columbia repurchased $200 million of stock in Q1 2026, after a $100 million repurchase in 2025 under the same $700 million plan. As of March 31, 2026, $400 million remained.

The bear case is also clear. Transactional real estate loans are running off, and new relationship loans must replace enough of them to protect net interest income. Non-performing assets also rose in Q1. Management said the increase came mainly from one agricultural relationship, but investors need a few more quarters of proof.

May 2026The Q1 2026 10-Q confirmed another $200 million of stock repurchases and left $400 million under the plan. It also kept the June 30, 2026 cost savings timeline in place.
Apr 2026Management said the Pacific Premier systems conversion was complete and that $102 million of the targeted $127 million in synergies had been achieved. That reduced the main integration risk.
Feb 2026The 2025 10-K confirmed the same post-merger plan: finish systems work, realize cost savings by mid-2026, and use the $700 million buyback plan.
Jan 2026Management guided to $150 million to $200 million of quarterly repurchases in 2026 and gave a clearer cost savings timeline. That made the capital return thesis more concrete.
Nov 2025The first 10-Q after the Pacific Premier close showed integration progressing as planned. It also confirmed runoff in commercial development and transactional loans.
Oct 2025Columbia closed Pacific Premier and announced a $700 million share repurchase program. The story shifted from deal approval to post-merger execution.
Aug 2025The Q2 2025 10-Q kept the Pacific Premier closing on track, with no major change to the core thesis.
Jul 2025Management said the Pacific Premier deal could close as early as September 1, 2025. Core operating performance also looked healthy before the integration work began.
02 Business model

A bigger Western bank, run for mix

Columbia makes most of its money the usual bank way. It gathers deposits, lends that money out, and earns the spread between loan yields and funding costs. In Q1 2026, net interest income was $594 million, far larger than non-interest income of $83 million.

The bank now operates across Arizona, California, Colorado, Idaho, Nevada, Oregon, Texas, Utah, and Washington. Pacific Premier added scale, especially in Southern California, but management says it has little interest in more M&A for now. The focus is on making the combined bank more efficient.

A key part of the plan is shrinking lower-return transactional loans and growing relationship-based commercial business. Columbia says it does not need net balance sheet growth to hit its earnings and return targets. That is helpful if the mix improves, but risky if runoff is faster than new production.

Deposits are just as important as loans. Total deposits were $53.5 billion at March 31, 2026, down from year-end because the bank intentionally reduced higher-cost brokered deposits. If customer deposits do not grow enough, funding costs could pressure the margin.

03 Product portfolio

Commercial clients drive the menu

Growth engine

Commercial and industrial lending

This is the loan growth area management wants most. The goal is relationship lending tied to deposits, treasury services, and fee income.

Steady

Owner-occupied commercial real estate

These loans finance business properties used by the borrower. They fit the relationship banking strategy better than stand-alone real estate deals.

Steady

Transactional real estate loans

Columbia is actively managing down inherited transactional loans, including parts of the multifamily book. Runoff helps the mix, but it can also shrink earning assets.

Growth engine

Treasury management and commercial cards

These services help business customers move, store, and manage cash. They can add fee income and make deposits stickier.

Option

Financial services, trust, and wealth

These businesses add fee income that is less tied to loan growth. In Q1 2026, financial services and trust revenue was $15 million.

Steady

Residential mortgage banking

Columbia offers home loans, but the strategy is mainly to originate and sell them rather than hold them. This serves existing customers without adding as much balance sheet risk.

04 Business segments

Loan book tells the mix

Commercial real estate loans58%declining
Commercial loans and leases26%modest
Residential loans16%declining
Consumer and other loans0%declining

The mix uses the Q1 2026 loan and lease table from the Form 10-Q. Columbia reports as a bank, so this view shows loan portfolio exposure rather than separate operating divisions.

05 Risk factors

What could break the setup

Cost savings do not hold

High impact · Medium odds

Management expects all disclosed Pacific Premier cost savings by June 30, 2026. If the Q3 expense run rate does not drop, the merger math gets weaker. The market may then treat the deal as larger, not better.

We watchQ3 2026 non-interest expense, excluding merger items and CDI amortization.

Loan runoff beats new production

High impact · Medium odds

Columbia is shrinking inherited transactional loans on purpose. That helps quality and mix only if new commercial relationship loans replace enough of the runoff. If total loans keep falling, net interest income can come under pressure.

We watchTotal loans and leases, C&I production, and management comments on transactional loan runoff.

Agricultural credit stress spreads

Medium impact · Medium odds

Non-performing assets rose to $264 million, or 0.40% of assets, at March 31, 2026. Management said the increase mainly came from a single agricultural relationship. If more categories weaken, the credit story changes.

We watchNon-performing assets, non-performing loans, charge-offs, and criticized loans by category.

Buybacks slow down

Medium impact · Medium odds

The stock repurchase plan is a major part of the thesis. Columbia bought back $200 million in Q1 and had $400 million left under the authorization. Repurchases can slow if capital, market conditions, credit losses, or regulators demand more caution.

We watchQuarterly repurchase dollars and CET1 capital ratio.

Funding mix worsens

Medium impact · Medium odds

Columbia is trying to lower reliance on higher-cost brokered deposits and wholesale funding. That helped the funding story in Q1, but customer deposits still need to support the loan book. If deposit costs rise again, net interest margin could compress.

We watchCost of interest-bearing deposits, brokered deposit balances, and net interest margin.
06 Quick answers

In one breath

What does Columbia Banking System do?

Columbia is a regional bank in the Western U.S. It takes deposits, makes loans, and offers services like treasury management, cards, trust, wealth, and mortgage banking.

Why did Columbia buy Pacific Premier?

The deal added scale and density, especially in Southern California. The current plan is to integrate the banks, cut costs, improve the loan and deposit mix, and return excess capital to shareholders.

Is Columbia still buying other banks?

Management has said the focus is not on more M&A for now. The story has shifted to integration, balance sheet optimization, and the $700 million share repurchase program.

What is the main risk for COLB stock?

The main risk is that the post-merger plan does not show up in clean earnings. Watch Q3 expenses, loan growth versus runoff, credit quality, and whether buybacks continue.