Copper exchange traded funds have seen a much weaker bounce than U.S. stocks in October, which raises some questions about the rally in risky assets.

Copper prices and the S&P 500 have shown a tight correlation in recent years, and many technical analysts use the red metal to keep their finger on the pulse of the global economy.

“This is a big negative divergence on copper and it may be that copper will accelerate to the upside soon, but while this negative divergence persists copper is arguing for lower prices,” the Channels and Patterns blog writes Thursday.

The iPath Dow Jones- UBS Copper Sub-Index Total Return ETN (NYSEArca: JJC) has traded lower this week and was down about 2% in early trading Thursday. [Copper and Silver ETFs Hit By Economy, Position Limits]

The exchange traded note is designed to track copper futures.

First Trust ISE Global Copper Index Fund (NASDAQ: CU) and Global X Copper Miners ETF (NYSEArca: COPX), which invest in copper miner stocks, were also lower Thursday.

iPath Copper ETN

The opinions and forecasts expressed herein are solely those of John Spence, and may not actually come to pass. Information on this site should not be used or construed as an offer to sell, a solicitation of an offer to buy, or a recommendation for any product.