As stocks have slipped lower over the last three months, copper has bucked the broad trend and broken the pattern of lower highs and lower lows it set in the spring.

After bottoming on June 7, the iPath Dow Jones-UBS Copper Subindex Total Return ETN (JJCC) - which closely tracks copper futures - has gained more than 12.2%. In the same span, the Russell 2000 small cap stock index has lost 0.6%.

Even a devout follower of financial news may have missed it; that is, the real engine behind renewed bullishness is the continuation of the China growth story.

Granted, there’s been a variety of exceptional earnings reports, including UPS (UPS), 3M (MMM), Apple (AAPL), Qualcomm (QCOM) and Pepsico (PEP). However, plenty of others expressed ”unusual uncertainty,” such as Amazon (AMZN), Google (GOOG), Starbucks (SBUX) and Bank of America (BAC).

By Brad Zigler

In early July, we reported a significant change in the commodity space ("Commodity Futures Outperforming Stocks") when producer stocks were lapped by the performance of futures. That's not the only change afoot, however.