Clients of the largest U.S. banks withdrew funds this month at the fastest weekly pace since the Sept. 11 attacks as a deposit-insurance program ended and customers tapped into their year-end cash hoards.

Net withdrawals at the 25 largest U.S. lenders totaled $114.1 billion in the week ended Jan. 9, pushing deposits down to $5.37 trillion, according to Federal Reserve data released last week.