Why regulators seized Signature Bank in third-biggest bank failure in U.S. history

On Friday, Signature Bank customers spooked by the sudden collapse of Silicon Valley Bank withdrew more than $10 billion in deposits, a board member told CNBC.

That run on deposits quickly led to the third-largest bank failure in U.S. history. Regulators announced late Sunday that Signature was being taken over to protect its depositors and the stability of the U.S. financial system.

The sudden move shocked executives of Signature Bank, a New York-based institution with deep ties to the real estate and legal industries, said board member and former U.S. Rep. Barney Frank. Signature had 40 branches, assets of $110.36 billion and deposits of $88.59 billion at the end of 2022, according to a regulatory filing.

“We had no indication of problems until we got a deposit run late Friday, which was purely contagion from SVB,” Frank told CNBC in a phone interview.

Problems for U.S. banks with exposure to the frothiest asset classes of the Covid pandemic — crypto and tech startups — boiled over last week with the wind down of crypto-centric Silvergate Bank. While that firm’s demise had been long expected, it helped ignite a panic about banks with high levels of uninsured deposits. Venture capital investors and founders drained their Silicon Valley Bank accounts Thursday, leading to its seizure by midday Friday.

That led to pressure on Signature, First Republic and other names late last week on fears that uninsured deposits could be locked up or lose value, either of which could be fatal to startups.  

Signature Bank was founded in 2001 as a more business-friendly alternative to the big banks. It expanded to the West Coast and then opened itself to the crypto industry in 2018, which helped turbocharge deposit growth in recent years. The bank created a 24/7 payments network for crypto clients and had $16.5 billion in…