Tom Hayes, the first trader jailed worldwide for interest rate rigging, lost his appeal against his conviction in a London court on Wednesday. Hayes, a former star Citigroup and UBS trader, was convicted in 2015 of conspiracy to defraud by manipulating Libor, a benchmark rate once used to price trillions of financial products globally. Prosecutors said Hayes and other traders were acting illegally by taking their or their employer's commercial interests into account when they made submissions on the London interbank offered rate (Libor).