In the wake of the subprime debt meltdown, lots of prime brokers moved to boost their margin requirements. You can't blame them. But there are some unintended consequences that some are now talking about. Standard & Poor's notes that some funds would like to plunge into distressed securities, which would buoy the overall market, but are on the sidelines in part due to margin issues. At the same time, higher margins may also result in more hedge funds being forced to deliver and thus sell assets, which could make it that much harder for the overall market to recover. Interesting. But I do not see the top brokers opening the spigots up really wide anytime soon.

For more:
- here's an article on the Institutional Investor website