On May 2, 1990, at 9.38 am in Nicholas Lane, London, UK, John Goddard was doing his daily courier round from Sheppard's money brokers. Suddenly a mugger held the courier at knifepoint and grabbed his briefcase. This was no ordinary mugging as the briefcase contained almost 300 bearer bonds worth a total of $435 million. However, as well as being one of the biggest muggings it was probably the most unprofitable at the same time - by midday, every major bank had been warned not to accept the certificates meaning that the thief was unable to trade them.
Source:Guinness World Records