It is often said by the wine trade that fine wine price don't appear closely correlated with the major share indices. So what is fine wine correlated with? Although fine art is often mentioned by commentators, in fact it is the number of billionaires in the world that appears to have the closest correlation with wine prices. The chart below plots the number of billionaires in the world as calculated by Forbes Magazine against the Liv-ex 100 Fine Wine Index (values taken each May when the Forbes survey is published).

We shared our findings with Jancis Robinson MW, who covered it on her website (no subscription necessary).