The past six months or so has been a little more sobering. After hitting a high point in May, prices have fallen, in some cases substantially. This is perhaps best illustrated by the copper market. Prices hit record highs of $8,600 a tonne on May 11, before falling by 24% in just five weeks. Copper for three-month delivery on the London Metal Exchange is currently at around $5,640 a tonne.

So how have those relative newcomers to the market, the long-only passive index investors, reacted to th