Hedge funds have enjoyed their best year-to-date returns in a decade, according to new research, but the majority of firms are still unable to charge performance fees to their investors, highlighting again the extent to which the industry suffered in 2008.

The hedge fund industry returned 12% to investors between the start of the year and July 31, according to figures from publisher Hedgefund.net, but 54% of all funds are still below the peak performance levels achieved at the start of last year.