Small-Cap ETFs are leading the markets charge this year. Year-to-date, the iShares Core S&P Small-Cap ETF (NYSEArca: IJR), which tracks the S&P Small-Cap 600 Index, increased 10.9%; the iShares Russell 2000 ETF (NYSEArca: IWM), which tracks the benchmark Russell 2000 Index, gained 9.2%; and...