Banks don't have to record losses on changes in those securities' value, cutting into their capital, unless the debt is sold. Still, holdings in that bucket, which carry minimal or no credit risk, were nonetheless showing a loss of about $109 billion at the end of 2022 due to the rise in interest rates over the past year.

This compares with losses of $36 billion for a similarly classified bond portfolio at JPMorgan Chase (JPM), $41 billion for Wells Fargo (WFC), and $25 billion at Citigroup (C) and just $1 billion at Goldman Sachs Group (GS), based on each company's 10-K filings with the Securities and Exchange Commission..

Attention on banks' bond losses has increased since regulators seized Silicon Valley Bank on Friday. SVB Financial, the lender's parent, had a $15 billion unrealized loss on its $91 billion held-to-maturity bond portfolio. That was equivalent to nearly all its $16 billion of tangible capital.

Eoin Treacy's view

It’s cruel irony that banks are currently experiencing a version of negative equity when homeowners have only been made whole after 15 years of waiting for price to recover following the Global Financial Crisis. The recovery will also be similar. Either they will need to make bigger profits, write-off the loss, be bailed out by the government or Fed, and lastly for bonds and stocks to make a full recovery.