Oil is getting most of the attention, but another commodity has been soaring in recent weeks. Copper, the red metal with supposedly predictive powers about the global economy, is on a tear.

Over the past month, the iPath Dow Jones-UBS Copper Subindex Total Return ETN (NYSEArca: JJC) is up nearly 8.8%. Copper miners, as measured by the Global X Copper Miners ETF (NYSEArca: COPX), have been nearly twice as good. COPX has surged 17.3% over the past 30 days.

Speaking of copper miners, ebullience surrounding the red metal has trickled down to theiShares MSCI Chile Capped ETF (NYSEArca: ECH), the lone ETF dedicated to tracking equities in the world’s largest copper-producing country. ECH is up 2.4% over the past month and with a year-to-date gain of 7.4%, ECH earns the title of best-performing Latin America single-country ETF this year. To its credit, ECH has that title by a wide margin over rivals ranging from the iShares MSCI Brazil Capped ETF (NYSEArca: EWZ) to the iShares MSCI All Peru Capped ETF (NYSEArca: EPU). [Copper Crimps Chile ETF]

When looking at ECH, the ETF’s correlation to copper prices is not readily apparent. The ETF’s materials sector weight is just 11.3%, or 650 basis points below the fund’s weight to bank stocks and well below the almost 29% allocated to the utilities sector. In fact, there is just one materials stock found among ECH’s top 10 holdings. However, ECH’s five-year correlation to JJC is 0.6.

The recent weakness in the U.S. dollar also bolstered hard assets, such as copper, which tend to have an inverse relationship with the greenback – a weaker greenback means that it takes more to acquire the same amount of copper.