While the current market price for natural gas may fluctuate, the long-term picture is quite bullish. It remains a much cleaner alternative for power plants over coal. It’s also a lot safer option than nuclear.

Over the next few years the United States will start exporting natural gas as a number of export facilities come online. There’s a great demand from overseas for liquefied natural gas (LNG), especially cheap gas produced by the U.S. fracking boom.

Yet natural gas prices have taken a beating in recent months, sinking below $4 per thousand cubic feet (Mcf) as demand has fallen off amid an unusually cool summer. Last month, my colleague David Sterman concluded that prices likely haven't bottomed out yet -- but they're bound to eventually. That's drawn the attention of a couple of high-profile billionaire investors, as I'll explain momentarily.

My three favorite companies to profit from the eventual rebound in natural gas prices are EQT Corp. (NYSE: EQT), Rice Energy (NYSE: RICE), and WPX Energy (NYSE: WPX).

The largest of these three companies, EQT controls over 3.6 million acres, including 580,000 acres in the Marcellus Shale region, one of the most prolific areas for natural gas production. EQT has about 8.3 trillion cubic feet of proved natural gas reserves. It also has stakes in EQT Midstream Partners (NYSE: EQM), a master limited partnership (MLP) that EQT spun off in 2012.

When natural gas prices fell to $2 two years ago, many producers turned their attention away from the natural-gas-rich Marcellus Shale region. EQT did the opposite and increased its presence in the Marcellus. Of the 89 wells EQT drilled during the second quarter, 55 were in the Marcellus, sending the company's sales volume in the region up 25% from a year ago. EQT's second-quarter results were strong, with earnings per share (EPS) up 28% from the same period last year, to $0.73.

Rice Energy (which my colleague David profiled in his article last month) is focused on the Marcellus, too, but it aIso has operations in the Utica Shale in Ohio. In June, Rice's first well in the Utica delivered production of 41.7 million cubic feet (MMcf) a day -- among the best-performing wells ever drilled in the formation.

Rice Energy has been very active this year since its IPO in January. Last month, Rice Energy acquired 22,000 net acres and 12 developed wells in the Marcellus from Chesapeake Energy (NYSE: CHK) for $336 million. This increased Rice’s net acreage by 24%.

Rice Energy is a family affair: The Rice family is the largest shareholder, and four members of the Rice family are involved in operations or on the board. The family patriarch, founder Daniel Rice III, has over 30 years of experience in the oil and gas business. Before starting Rice Energy in 2007, he was the lead portfolio manager of BlackRock’s (NYSE: BLK) global resources investments.

Moving on to WPX's key growth opportunity lies in Colorado's Piceance Basin, which is the company's largest area of concentrated drilling. WPX is planning to use an MLP to hold working interests in its mature properties in the basin.

A number of hedge fund managers are investing in these companies as a play on rising natural gas prices. Billionaire Ken Griffin and his Citadel Advisors own almost 3% of WPX and nearly 4% of Rice Energy. George Soros’ stake in EQT is worth $250 million.

Risks to Consider: While the prospect of natural gas as a long-term sustainable fuel source is well known, the switch to natural gas can be long and drawn out. Low natural gas prices also mean less revenue for natural gas companies. If prices remain distressed for an extended period it means less revenues for the three companies above.

Action to Take --> Follow the likes of Griffin and Soros and buy shares of EQT, RICE and WPX. All three should benefit as natural gas demand rebounds and the U.S. begins to allow natural gas exports.