How much further could stock markets fall?

It's been a grim couple of days for global stock markets. Indeed, it's been a pretty bad year so far in fact. The first quarter was fine, but since April markets have struggled. So far in 2010, reports the Financial Times, the FTSE All-World Share Index is down by more than 10%, while safe havens have been the big winners. US treasuries have returned 5.8%. The dollar is up 10.5% on a trade-weighted basis. And gold is one of the top performers, up 13%.