ETFs to Watch August 6, 2013 (BSV, KOLD, THD)

Here is the ETF Professor's ETF Watch List for Tuesday, August 6, 2013. Keep an eye on the Market Vectors Biotech ETF (NYSE: BBH ). The ProShares UltraShort DJ-UBS Natural Gas (NYSE: KOLD ) is worth a look. So is the Market Vectors Semiconductor ETF (NYSE: SMH ). Emerging markets plays