Top U.S. hedge fund management firms, including David Einhorn's Greenlight Capital and Philippe Laffont's Coatue Management, reduced their stakes in Apple Inc during the fourth quarter, ahead of the iPhone maker's strong rally in 2015, according to regulatory filings.

Apple was a big winner in 2014, with its shares rising nearly 38 percent. The company's stock is up more than 16 percent year to date and reached an intraday record high of $129.45 per share. Last week, its stock market value rose above $700 billion, bigger than Switzerland's gross domestic product.

Although Apple is the biggest position in Coatue Management's portfolio, the firm sold 1.7 million shares at the end of the quarter, or more than 15 percent of its stake, leaving it with 8.9 million shares, according to a regulatory filing on Tuesday.

In a filing on Friday, Greenlight said it cut Apple holdings by 6.2 percent to 8.6 million shares during the quarter.

Eric Mandelblatt's Soroban Capital Partners sold 4.3 million Apple call options, liquidating the fund's position. And David Tepper's Appaloosa Management hedge fund said it had dissolved its stake in Apple, while Leon Cooperman's Omega Advisors sold 808,000 Apple shares to own 383,790 shares at the end of the fourth quarter.

Last week, billionaire activist investor Carl Icahn said the technology company's shares should be trading at $216 apiece, equivalent to a market capitalization of $1.26 trillion.

The actions by Greenlight and Coatue were revealed in quarterly disclosures of manager stock holdings, known as 13F filings, with the U.S. Securities and Exchange Commission. They are of great interest to investors trying to divine a pattern in what savvy traders are selling and buying.

But relying on the filings to develop an investment strategy comes with some peril because the disclosures are backward-looking and come out 45 days after the end of each quarter.

Still, the filings offer a glimpse into what hedge fund managers saw as opportunities to make money on the long side.

The filings do not disclose short positions, or bets that a stock will fall in price. As a result, the public filings do not always present a complete picture of a management firm's stock holdings.

The following are some of the hot stocks and sectors in which hedge fund managers either took new positions or exited existing positions in the fourth quarter.

ACTAVIS PLC

Coatue Management opened a new position, buying 964,155 shares, as drugmaker Actavis won a high-stakes battle to buy Botox maker Allergan Inc.

Daniel Loeb's Third Point upped its stake by 20 percent to 3.5 million shares. But Neil Chriss' Hutchin Hill cut its position by 13 percent, selling 17,201 shares to own 28.3 million at the end of the quarter.

Omega Advisors upped its stake by 237,100 shares to own 943,572 shares.

AGRIUM INC

Activist investor ValueAct bought 2.9 million shares of the Canadian fertilizer producer to own 8.2 million at the end of the quarter.

AMGEN INC

The biotechnology company is being pressured by hedge fund investor Daniel Loeb to break itself apart.

Alex Denner, who now runs Sarissa Capital after working for Carl Icahn, upped his stake by 165 percent to 50.6 million shares.

BAKER HUGHES INC

Farallon Capital Management bought 3.5 million shares, a new position, of the oilfield services company, which will be bought by rival Halliburton Co.

Activist fund ValueAct Capital took an even bigger new position, buying 14.9 million shares. ValueAct also took a 20.9 million-share stake in Halliburton.

Omega Advisors took a new stake in Baker Hughes of 65,500 shares and sold its entire 1.9 million-share stake in Halliburton.

BANK OF AMERICA CORP

John Burbank's Passport Capital, which made money early this year by betting against energy exchange-traded funds, added a position in Bank of America, buying 2.8 million shares.

CITIGROUP

Leon Cooperman's Omega Advisors cut its stake in the bank by 915,200 shares to 4.2 million shares.

EBAY INC

Jon Jacobson's Highfields Capital upped its stake in online commerce company eBay by 39 percent by adding 1.8 million shares to own 6.5 million at the quarter's end. Third Point bought 5.5 million shares to own 10 million shares, while Omega Advisors raised its stake by 375,200 shares to 3.5 million shares.

FACEBOOK INC

Tiger Consumer cut its holdings in the online social network operator by 28 percent to 854,980 shares. Aaron Cowen's Suvretta Capital bought 629,600 shares, putting on a new position.

GENERAL MOTORS CO

Caxton Associates made a new bet, buying 1.2 million shares of the automaker.

LIBERTY GLOBAL PLC

Coatue raised its stake in the European cable operator by 34 percent, purchasing 1.4 million shares to own 5.6 million shares. Tiger Consumer sold 527,956 shares, giving it 1.5 million shares.

NETFLIX INC

Coatue cut its position by 13 percent, selling 287,415 shares to own 1.8 million shares. Tiger Consumer, however, opened a new position in the provider of on-demand Internet streaming services, buying 182,098 shares.

TESLA MOTORS INC

Highfields Capital took on a new position in the high-end electric car maker, buying 91,296 shares. Tesla shares fell late last year but climbed anew in early 2015.

SUNEDISON INC

Third Point nearly doubled its stake by buying 5 million shares to own 11.2 million. Omega Advisors increased its stake in the solar power company by 1.2 million shares to 9 million shares.

YAHOO INC

Passport Capital slashed its position by 81 percent, selling 6 million shares in the search engine company to own 1.4 million at the end of the quarter.

ZOETIS INC

The animal health company, which made headlines when activist investors William Ackman and Scott Ferguson bought big stakes, also saw new interest from other hedge funds. Highfields Capital bought 252,000 shares.