As for the gold I really don't have an explanation. Somehow investors understood by then that gold was on a secular bull without end in sight.
Some people claim that gold is still manipulated by central banks that avoid strong appreciations by dumping reserves on the market. I can't say how true these concerns are, but gold surely evolves in a different way than other metals. The fact that gold has depreciated so much in latest months (against crude oil) is by itself a riddle to me. Vencit omnia veritas.
I said May because amazingly all the curves converge to a point (to within visual accuracy) at that time. Somehow the indices get pinched and then they start diverging. Can the last politician to go out the revolving door please turn the lights off?