Frederic, there is a futures market based in NY that trades a sufficient volume to hedge nearly the entire DR yearly crop. There is also a futures market in london (liffe.com).
http://www.nyce.com/
As Shadley000 mentions, an important question is how correlated the export price for DR cocoa is the the NYC and London (liffe.com) markets.
When someone buys the "flowers", what percentage do they ususally pay, assuming an average crop yield?
thanks again,
mondongo