NEW YORK (TheStreet) -- Bets on airlines, biotech and China internet paid off well for billionaire investors in 2014. David Tepper made millions on American Airlines (AAL) - Get American Airlines Group, Inc. Report , Seth Klarman did well with Idenix (IDIX) , and both Chase Coleman and George Soros hit the nail on the head with Vipshop (VIPS) - Get Vipshop Holdings Ltd Sponsored ADR Report .

Which stocks, sectors and strategies will prove the biggest moneymakers in the year ahead? Where will billionaires be investing in 2015? A few predictions.

Oil Opportunities

Oil prices are plunging, and by the looks of it, they haven't bottomed out yet. Crude oil hit a new five-year low yesterday in the wake of OPEC's slashed production estimate. Bank of America has predicted prices could go as low as $50 per barrel in 2015, and some have suggested it could even hit $40.

Translation: a tough outlook for energy stocks, many of which have already plummeted.

Billionaires have found themselves among the collateral damage -- especially Carl Icahn and Leon Cooperman. Icahn picks Transocean (RIG) - Get Transocean Ltd. Report , Chesapeake Energy (CHK) - Get Chesapeake Energy Corporation Report  and Talisman Energy (TLM)  have tumbled in recent months, and in an October interview with CNBC, Cooperman called Omega's 15% energy allocation one of his "mistakes this year."

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There is, of course, a flip side to all of this, tied to inflation, equity valuations and, most importantly, consumer spending.

Credit card giants MasterCard (MA) - Get Mastercard Inc. (MA) Report , Visa (V) - Get Visa Inc. Class A Report  and American Express (AXP) - Get American Express Company Report  have been garnering the attention of billionaire investors already this year, including George Soros, Ray Dalio and, of course, Warren Buffett. Strong earnings reports indicate the companies are gaining momentum, and as consumer spending (and, in turn, credit card use) rises, that will likely continue.

Auto stocks may also come into view, including those which struggled in 2014, including Ford (F) - Get Ford Motor Company Report  and General Motors (GM) - Get General Motors Company (GM) Report . But billionaires may be hesitant in light of the regulatory and strategic implications falling oil prices have on the auto industry. Where they may look instead? E-commerce (hello, eBay (EBAY) - Get eBay Inc. Report ) and consumer discretionary. And even though energy stocks are declining, billionaires may take advantage of discount deals.

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High on Health Care

Glenview Capital Management's Larry Robbins made a bet early on that Obamacare would have big implications for the health care industry in the United States. His instincts have turned him into one of the top-performing hedge fund managers in recent years, and by the looks of it, other Wall Street magnates are following his lead.

The latest rebalance of the iBillionaire Index demonstrates a marked trend toward investing in health care stocks among billionaire investors. Stocks in the mix include names like Thermo Fisher Scientific (GMO) - Get General Moly, Inc. Report , Tenet (THC) - Get Tenet Healthcare Corporation Report , Actavis (ACT) - Get AdvisorShares Vice ETF Report  and Aetna (AET) .

Health care has been one of the best-performing sectors of 2014 -- a trend that stands to continue. PricewaterhouseCoopers anticipates that 2015 will be a "revelatory year" for the sector as a portrait of 10 million newly insured individuals emerges.

A new batch of M&A deals are also on the horizon as well, meaning the long-fought battle for Allergan (AGN) - Get Allergan plc Report  -- which will likely be won by Actavis (ACT) - Get AdvisorShares Vice ETF Report  -- is just the tip of the iceberg. Bill Ackman seems to already be positioning himself for another big health care play in 2015 with his new stake in animal-focused company Zoetis (ZTS) - Get Zoetis, Inc. (ZTS) Report .

Seeking Spinoffs

According to investment analysts at The Edge and Deloitte, the market capitalization of the companies undertaking spinoffs in 2014 is set to hit $664 billion by the end of the year. Moreover, the value of corporations that have already announced spinoffs for 2015 is at $775 billion.

eBay's PayPal spinoff will surely be one of the most anticipated deals of the year, and Carl Icahn, Julian Robertson, Dan Loeb, Larry Robbins and others stand to profit. But that's not the only split billionaires will be on the lookout for in 2015.

Energizer Holdings (ENR) - Get Energizer Holdings Inc Report  will spin off its household products business in July -- a move Dan Loeb could very well take advantage of, given his new million-share ENR stake. Also with spinoffs in the pipeline for 2015 are Baxter International (BAX) - Get Baxter International Inc. Report  -- a Ray Dalio and Richard Chilton holding -- and Atlas Energy (ATLS) , in which Leon Cooperman has been upping his stake in recent weeks.

Spinoff investments can be profitable ones. The Edge and Deloitte analysts found that parent companies gained an average of 14% in the first year after splitting and 28% after the second. Spinoff entities climbed an average of 22% during year one and 48% in year two.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.