[wpietri]

In some sense, they're still not. Derivatives don't require much involvement in the underlying commodity. For example, consider weather derivatives:

https://en.wikipedia.org/wiki/Weather_derivative

E.g., the CME's weather futures and options:

http://www.cmegroup.com/trading/weather/

It's not like the Merc is really involved in weather. They just let people gamble on the weather.