That gets chalked up to Stumpf playing with his grandchildren, according to a spokeswoman for the bank. She declined to provide specifics on how it happened.
Although Stumpf's hand was wrapped with enough bandages to make him look like an injured athlete, it probably was not the biggest source of pain for the Wells Fargo CEO on Tuesday.
The hearing on Capitol Hill where Stumpf testified showcased lawmakers eager to dig into the bank's business practices that led to a $185 million fine from agencies including the Consumer Financial Protection Bureau.
Sen. Elizabeth Warren on Tuesday told the CEO he should be "criminally investigated" for his role in the bank's faked accounts, and Sen. Robert Menendez called the bank's sales and management culture "despicable."