On 3 February 2026 Banco Santander agreed to acquire Webster Financial for $12.2 billion in cash and shares: $48.75 in cash plus 2.0548 Santander ADSs for each Webster share, valued at $75 per share at announcement[1]. Santander says the combined business will be a top-ten US retail and commercial bank by assets, with around $327 billion of assets, and a top-five deposit franchise in the US Northeast. Closing is expected in the second half of 2026.

Two months on, with the market's first reaction behind us, the deal is worth a closer look, because it says a lot about what US bank franchises are worth right now.

Read the funding numbers first

Santander's own presentation of the rationale is unusually direct about funding. The combination improves the US business's loan-to-deposit ratio from 109% to about 100%. Santander brings consumer finance strength to the US, but a ratio above 100% means it has funded part of its lending from sources more expensive than customer deposits. Webster brings roughly the opposite profile: commercial banking relationships and a deposit base.

The targets follow from that. Santander is aiming for about $800 million of annual cost synergies, 19% of the combined cost base, an efficiency ratio below 40% and a US return on tangible equity of 18% by 2028.

In this market, buyers are not paying for branches or loan books. They are paying for deposits that do not leave.

Why commercial deposits command the premium

Not all deposits are equal. Rate-sensitive retail savings can move quickly to whoever pays more, as 2023 showed. Commercial operating deposits are different. They sit in accounts that businesses use to pay suppliers and staff, they come with treasury management services, and they are expensive for a company to move. A bank that holds them has a relationship, not just a balance.

That is what makes mid-sized commercial banks attractive targets. For a buyer with a funding gap, acquiring a commercial deposit franchise is faster and more certain than building one organically, which takes years of relationship banking and treasury technology investment.

What this means for other banks

Three implications for boards and executive teams:

  1. Know your deposit franchise value. Break deposits down by type, stability and cost, and understand how a buyer would value them. That number frames every strategic option, including remaining independent.
  2. Protect the treasury relationship. Commercial deposits are sticky because of treasury services. Underinvest in payments, liquidity tools and the commercial digital platform, and the deposits become rate-sensitive like any other.
  3. Expect more cross-border interest. A foreign group willing to pay for a US deposit franchise will not be the last. Regional banks with strong commercial deposit bases should assume they are on buyers' lists, whether or not they are for sale.

The Webster deal will be judged on integration and the 2028 targets. Its lesson for everyone else is available now: in US banking, the scarce asset is stable funding.