Until recently, investors’ defined commodities as anything from "generic goods used to make more valuable items" to "a high-performing asset class that diversifies a portfolio and offers protection against a falling dollar, inflation, world calamity, and just about anything else." Can you blame them? Since 2000, commodity indexes have outpaced nearly every other asset class. While the S&P 500 continues trying to claw its way back to where it was nearly a decade ago, commodities, especially oil – the Grand Poobah of commodities – just keeps climbing.