Hedge fund, succumb. Pools of capital from supposedly sophisticated investors will no longer roam free. US Treasury secretary Tim Geithner wants all sizeable funds to register with the Securities and Exchange Commission. This is hardly onerous. It would effectively reinstate powers the SEC had before the courts intervened in 2006. Inspection of internal controls, for example, is also uncontroversial given the post-Madoff focus on investor protection.

Mr Geithner, however, also wants information to assess possible systemic risks. That is more complex. First, given hedge funds’ protective attitude to their trading secrets, regulators will need to distinguish between the increased transparency they require and that made available to the public. Second, existing trading reports exclude over-the-counter derivatives and consist of forms capturing the what without the wherefore (a short position could be a hedge or a negative bet on a stock’s prospects). But even with improved information, regulators would still struggle to assemble a picture of the hedge fund universe. Without that, they cannot spot so-called “crowded trades”, which prove problematic when everyone tries to exit at once. Extra data from prime brokers and exchanges, say, could help.