The fall of Boaz Weinstein, once one of Wall Street's hottest traders, speaks volumes about why financial firms still are reeling from the shattered global markets.

As a chess master, poker and blackjack devotee and top trader at Deutsche Bank, Weinstein made big bets using complex financial instruments, generating large returns for the bank and about $40m (€31.2m) in annual pay for himself. But in 2008 the group he ran saddled the bank with $1.8bn in losses, erasing more than two years of trading gains.