The largest hedge funds lost more than 20% for 2015

The losses are adding up

Einhorn's fund is down about 12% in the past year, according to iBillionaire, which tracks hedge fund performance. That's a loss of about $1 billion.

It's mostly the result of Einhorn's large stake in Consol Energy (CNX), the Pittsburgh-based natural gas and coal company. The stock has lost over 65% of its value in the past year, but Einhorn believes it will double.

Icahn's fund has taken an even bloodier hit. It's down over 22% in the past year, according to iBillionaire. That's a loss of about $9 billion in value.

He is a big holder of CVR Energy (CVI), Chesapeake Energy (CHK) and Transocean (RIG). Natural gas company Chesapeake has fallen 70% in the past year and offshore drilling company Transocean is down 65%.

But fortunes can change quickly. While most Wall Street experts predict that prices will stay low, oil could rally quickly if China's slowdown doesn't turn out to be as deep or long as people fear.
"The last time I heard this many people so bearish on oil, we rallied $20 a barrel," says Phil Flynn, a senior energy analyst at the Price Futures Group in Chicago. He thinks Einhorn and Icahn may turn out to be right. Even with China's slowdown, he notes that the country's oil exports are on track to hit a record level this year.

That may explain why companies like CVR Energy are starting to bounce. The company, which does both oil refining and fertilizer production, is up over 10% in 2015.
The other way to play oil

Overall though, top hedge fund managers aren't scooping up oil stocks. They're doing the opposite: they are buying companies that will benefit from many more months of cheap oil.
"The bearishness isn't over yet," says Raul Moreno, CEO and co-founder of iBillionaire.

Moreno points out that top notch investors like Bill Ackman of Pershing Square, David Tepper of Appaloosa Management and Chase Coleman of Tiger Global have no positions in energy right now.
Coleman of Tiger Global has been buying stocks like Amazon (AMZN, Tech30) and TripAdvisor (TRIP) that should benefit from inexpensive shipping costs and travel spending from people who have more money in their pocket from lower price of gas.

Tepper appears to be thinking along similar lines. He increased his stakes in JetBlue (JBLU) and GM (GM) in the second quarter.