iPath Dow Jones-UBS Copper Total Return Sub-Index ETN (NYSEArca: JJC)
YTD: -11%
Comment: Bad news: Copper, once considered a useful indicator of global economic growth because of its widespread industrial application, has been declining while the world economy is expected to expand the most in three years.
Good news: JJC looks to be finishing the quarter on a strong note as emerging markets equities and ETFs, including some tracking China, have rallied. That is not a promise of a sustainable rally, but rather a reminder of how important China is to the copper market. [Doctor Copper Seeing Just One Patient: China]