Oil-linked exchange-traded funds have been posting solid gains, but these specialized funds are complex and risky instruments that don't fully capture oil-price moves.

Families who pack up the car this Fourth of July weekend will spend much less on gasoline than last year -- prices are down by more than a third from last summer. But when it comes to fueling your investment portfolio, a specialized exchange-traded fund may hedge against unwelcome oil-price spikes.

Which Oil ETF has been the best at capturing the upswing in crude oil prices?

Daring to drink the water of the emerging markets funds could prove to be little more than a way to tap into Montezuma's revenge. But history tells us that investors who discount the rewards are as prone to disappointment as those who dismiss the risks.

Marchâ??s mood has shifted from fear mongering to the prospect of a rosy outcome, but a firm floor for the market needs more than splinters of hope.