The interest rate behind trillions in loans turned out to be whatever traders wanted

Libor was supposed to reflect the real rate banks charged each other to borrow, and it underpinned everything from mortgages to derivatives worth hundreds of trillions of dollars. Investigations revealed that traders at major banks had for years been messaging the staff who set Libor's daily rate, asking for a number that would make their own bets more profitable. Barclays, UBS and others paid billions in fines, and several traders went to prison.

— UK Financial Conduct Authority, Libor scandal — Investigation findings published 2012