The news: Fifth Third announced that it would acquire Comerica, merging two large regional banks in a deal worth $10.9 billion. The combined bank will have about $288 billion in assets. That knocks BMO, which hold $253.7 billion in assets, including the $16.3 billion added through its Bank of the West acquisition in 2023, out of the top 10.

Movement at the top: Beyond the Fifth Third–Comerica and BMO–Bank of the West deals, several megabank mergers have reshaped banking since 2019.

• Capital One–Discover: Closed in 2025 in a deal worth $35.3 billion. Capital One is now the sixth-largest US bank.
• TD Bank–First Horizon: A $13.4 billion deal that collapsed in 2023 after TD failed to gain regulatory approval.
• US Bank–MUFG Union Bank US: Closed in 2022 for $5.5 billion. US Bank is still the fifth-largest US bank.
• BB&T–Suntrust: Closed in 2019 in a $66 billion deal, forming Truist, now the eighth-largest bank in the country.
• PNC–BBVA USA: Completed in 2021 for $11.6 billion. PNC announced in 2025 that it would buy FirstBank for $4.1 billion. It is now the seventh-largest bank.

This list excludes JPMorgan Chase’s rescue of First Republic in 2023.

The scale game: Bank mergers generally fall into two categories: community banks consolidating regionally (at least 20 this year), and large regional banks combining to achieve national prominence.

JPMorgan, Bank of America, Wells Fargo, and Citi are still at the top:

• The biggest regionals increasingly compete with each other. Leapfrogging in size through acquisition, they expand their branch networks and instantly acquire deposits and loans.
• Efficiencies are crucial. Megamergers help these banks distribute their spending across technology, compliance, and other large fixed costs.
• They face competitive pressure from Big Tech and fintech firms Even JPMorgan CEO Jamie Dimon has described nonbanks as an “enormous” threat.

Where this goes: The FDIC recently rolled back scrutiny of large-bank deals, and President Donald Trump signed a resolution repealing a Biden-era rule that tightened merger reviews. The door is now more open to mergers between large regional banks, and a new wave of consolidation could be coming.