Junk bond exchange traded funds have taken a beating this year, and the blows may not let up any time soon. Year-to-date, the iShares iBoxx $ High Yield Corp Bond ETF (NYSEArca: HYG) declined 10.4% and the SPDR Bloomberg Barclays High Yield Bond ETF (JNK) decreased 10.9%. Speculative-grade junk...