Options and the Gamma Knife

I survey work of Steve Ross (1976) and of Douglas Breeden and Robert Litzenberger (1978) that first showed how to use options to synthesize more complex securities. Their results made it possible to infer the risk-neutral measure associated with a traded asset, and underpinned the development of the VIX index. The other main result of Ross (1976), which shows how to infer joint risk-neutral distributions from option prices, has been much less influential. I explain why, and propose an alternative approach to the problem.