The financial development of agricultural markets is not recent. But, starting early 2000, a large amount of investments on commodity markets, including agriculture, have been realized using innovative instruments. And in 2007-08, the continuous increase of investment was simultaneous with prices increases. Speculation and price spikes were soon “correlated”. A controversial debate on the role of commodity investment funds emerge that induced G-20 decision in November 2011 to limit excessive price volatility on commodity markets through improved control of speculation on futures and OTC markets. The article is analysing the hypothesis that commodity funds are causing price volatility using first a direct relationship between the “Assets Und...