The last two or three years have been tough on commodity index funds. Most have lost money. However, rightly or wrongly, index funds are promoted as long-term investments in commodities for which demand will surely grow.All of us probably remember the so-called bubble in commodity prices in 2007 and 2008. Those were challenging times for producers and users of a wide variety of commodities including but not limited to gold, crude oil, grains, oilseeds, industrial metals and soft commodities. The severity of the challenges probably was best illustrated by the price action of the corresponding futures markets at the time. Futures prices for many commodities had begun to slowly edge higher in 2004 and 2005. They soared in 2007 and early 2008,...