Alan Greenspan is not only one of the foremost central bankers of his generation but also one of the most influential thinkers on the appropriate level of regulation for financial markets. It is perhaps no coincidence that during an early phase of his long career he was a member of the Commodity Exchange, Inc. Greenspan is close to completing his fifth and final term as chairman of the Federal Reserve Board, and throughout his long tenure at the Fed he has consistently supported the greatest possible freedom for financial markets in general and derivatives in particular. Time and time again he has defended the derivatives business—both exchange-traded and over-the-counter—from critics who sought greater government control over market forces. To give just one example, without his influence, over-the-counter trading in swaps, one of the great drivers of interest rate futures volume in the last two decades, might have been driven permanently offshore.