The Fed’s balance sheet expanded to a record $5.3tr in the week ended March 25 from $4.7 trillion in the prior week, as it scooped up bonds and extended loans to banks, in its effort to backstop the economy in the face of the pandemic. The Fed bought $355 billion of Treasuries and mortgage-backed bonds in the last week, and also offered more than $200 billion in credit to other central banks.