Investing: Can I profit from rising gas prices?

— -- Your investment portfolio isn't going to help you save on gasoline, unless you've discovered a way to make your car run on stock certificates. But if you want to profit from rising gas prices, you might want to wait a bit.

As you have probably noticed, gas prices have been soaring this year. A gallon of regular gas cost, on average, $3.59 a gallon the week ended Feb. 20, according to the U.S. Energy Information Administration. That's 40 cents a gallon higher than a year ago.

"The markets indicators make it a safe bet to predict $4 a gallon before Memorial Day," says Ben Brockwell, director of data, pricing and information services for the Oil Price Information Service.

You might think that higher gas prices are because of lower production, but you'd be wrong — especially if you were talking U.S. production. There are 1,272 oil rigs drilling in the U.S., vs. 798 a year earlier, according to Baker Hughes. The U.S. produced 8.88 million barrels of oil per day at the end of January, says the EIA, vs. 8.27 million a year earlier.

The U.S. has been importing oil since at least 1949, when Truman was still in office. Currently, the U.S. produces 51% of its petroleum and imports the rest. About 25% of imported oil comes from Canada, with Saudi Arabia accounting for 12%. But world oil production has increased since last year.

Rising demand doesn't appear to be behind the increase in gas prices, Brockwell says. "There have been nine weeks in the past 12 years where weekly U.S. demand has been below 8 million barrels a day," Brockwell says. "Four of them have been this year."

Why are oil prices rising? "That's a picture that's a bit difficult for us to unravel, even for those of us who are experts in the field," Brockwell says. Still, here are a few reasons oil prices have soared:

•The world economic outlook. "Economic growth in the U.S. is better than expected — not great growth, but taking small steps forward," says David Ginther, manager of the Ivy Energy fund. A resolution to the Greek debt problem could mean a shallower recession in Europe than was expected at the start of 2012.

•Emerging markets. Most people who have traded in a horse or a bike for a car have been glad they did. In emerging markets, such as China and India, car sales are booming — as is petroleum consumption.

•World unrest. Troubles in Syria, Libya and Iran have raised the fear of war in the Middle East. Others worry about an Arab Spring uprising in Nigeria, where about half the people are Muslim.

Can you make money from higher oil prices? Twenty-four exchange traded funds use futures to reflect the price of oil. Unlike garden-variety funds, these trade throughout the day on the stock exchanges.

But many ETFs that use futures to track the price of oil suffer from structural problems from having to roll over the futures contracts, which can create a drag on performance, says Kevin Disano, senior vice president at IndexIQ.

Oil and gasoline prices are already high. "As gasoline prices approach $4 a gallon, it really starts to have people thinking twice," says Bob Shearer, manager of Blackrock Global Energy and Resources Trust.

Similarly, demand for oil tends to fall when prices hit $130 a barrel. Brent crude sells for about $123 a barrel, while West Texas Intermediate closed at $107.83 Thursday. You may want to wait until prices drop back down before jumping into the oil market.