No-one has been willing to predict the impact of the rule the Securities and Exchange Commission will bring into effect in 10 days' time, formally forbidding hedge fund managers from making false statements to their investors, but it may be a smart way for the regulator to realise its goal of keeping tabs on the industry.

The rule has surprised many involved with hedge funds, who have pointed out that it is already against US law for anyone to make false statements knowingly and with the intent to make a profit.