ProShares Ultra Dow30(AMEX:DDM)

DDM is a short-term tactical tool that delivers 2x returns for a single day. Investors holding the fund for longer than a day will need to monitor and rebalance their position to achieve the 2x multiple. Aside from the leverage, DDM's underlying indexthe venerable Dow Jones Industrial Averagehas its warts despite its popularity. As an under-diversified, price-weighted index, the Dow Jones Industrial Average draws serious skepticism about its utility as the foundation for a long-term buy-and-hold strategy. Still, investors betting on short-term market moves might be less deterred by the Dow's shortfalls. As a short-term play, DDM's liquidity and associated trading costs are critical.