Thor Bjorgolfsson
Finance, Investment
Rank 2017

Bjorgolfsson once lost £3bn in three days. The Icelandic entrepreneur, who lives in London, was one of the biggest investors in his homeland's banks when the country's financial crisis erupted in 2008. He cancelled building work on a £100m yacht and issued a public apology before he and his creditors worked out a complex agreement to pay off debts of more than $1bn. The 50-year-old owns half of P4, one of Poland's largest mobile phone companies, where there has been talk of a £1.5bn sale or float.

How it feels to ... lose £3bn in three days