SVB used longer term US Federal Treasury notes as their backstop than appears to have been prudent. Maybe Credit Suisse did the same. Maybe MANY others. Remember, short term Treasuries were netting you close to 0% for the longest time. Many entities likely reached out further in the maturity timeline to get better returns. Now, the increases in the short term rates imposed by the FED are causing longer term bonds to be sold at fairly significantly higher rates. Nobody wants to buy the old bonds unless they get a steep discount on the purchase price. I mean, why buy a bond/note from 2019 earning 0.75% when you can buy a bond/note from March 2023 earning 4.75%? And, there we go.
However, if we think the FED will stop increasing interest rates then I have a bridge to sell you. Until the FED gets inflation under control they will raise rates. And, if our Federal government continues implementing inflationary policies then the FED will always be behind the curve. And, there we go.