Short-biased hedge funds had their best month since November 2007, gaining 9.02% in June, despite UK and US regulators making the practice of shorting shares more difficult.

According to data provider Lipper TASS, hedge funds that shorted shares made 11.95% in the first half of 2008 and 21.32% since July 2007. Shorting shares are carried out when traders borrow stock in a bet that the price will fall and can be repurchased at a lower price.