From Barron's today on BAC
Bank of America had $862 billion of debt securities on its balance sheet totaling roughly $3 trillion at the end of 2022. Of that, $632 billion of bonds, mostly federal agency mortgage securities, were classified as held to maturity for accounting purposes.
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.