One truly astonishing feature of this bout of speculation is that the average holding period of a commodity futures contract was just three hours in April, according to a Bloomberg article. That makes other speculative trading episodes look like long-term investing.

It also suggests a massive appetite for risk, which in and of itself, is potentially destabilizing, both in China and, by extension, elsewhere in the world.

Why do we care?

Well, first of all, the recent rebound in commodity prices, here at home, and the affiliated rebound in raw materials stocks, could have been driven, at least in part, by those very speculative excesses in China.