1. iPath Copper ( JCC).
Long-time readers know that I talk about Dr. Copper frequently. It may be one of the best indicators of investor confidence (or lack thereof) in the global industrial cycle. Therefore, your eyes should open up wide when JJC falls below a 200-day moving average. The last time that it happened? April to May 2010... at the inception of the S&P 500's nasty -17% correction.