In the end, the critics of hedge funds would do well to remember why this sector has emerged as such a force. Until the late 1960s, the financial world was quaintly stable: exchange rates were inflexible, interest rates were regulated, and the whole system was anchored by a fixed gold price. But that world collapsed when inflation drove the dollar off the gold standard and currencies and interest rates began to float; from then on, it became impossible to amass savings without facing financial uncertainty. Tools for coping with that uncertainty -- deep markets in futures, options, and other derivative instruments -- sprang up in response to the newly volatile environment. And hedge funds emerged as the masters of these tools, providing quasi insurance to investors and firms and introducing a healthy dose of contrariness into financial markets. For this, they are accused of generating risk. But their real systemic function is to manage it -- and it is their very success in doing so that has generated both their profits and their phenomenal growth.