The number of exchange traded funds rooted in the momentum factor continues proliferating, though that may not be a surprise at a time when the momentum factor is outpacing its value counterpart. Even with the increased population of such ETFs, momentum remains arguably one of the most critiqued investment factors. While the momentum factor has shown long-term durability against traditional broad market indexes, some ETFs have a way of over-complicating the factor (along with other investment factors), so perhaps the best application of momentum among ETFs is a simple approach. Enter the newly minted PowerShares S&P 500 Momentum Portfolio (NYSE: SPMO). Just as the popular PowerShares S&P 500 Low Volatility Portfolio (NYSE: SPLV) tracks the 100 S&P 500 with the lowest trailing 12-month volatility, the PowerShares S&P 500 Momentum Portfolio is currently home to 101 S&P 500 stocks displaying favorable momentum scores.