Icahn Enterprises

Billionaire activist investor Carl Icahn disclosed a new stake in EBay Inc. (EBAY), according to a regulatory filing on Thursday.

Mr. Icahn held 27.8 million shares in the online-auction company as of March 31.

The activist investor also raised his stake in Apple Inc. (AAPL) and decreased his stake in Netflix (NFLX).

Mr. Icahn raised his holdings in Apple by 2.8 million shares to more than 7.5 million shares, increasing his bullish bet on the iPhone maker.

In April, Apple increased its share-repurchase authorization to $90 billion from the $60 billion level announced last year. The company also increased its quarterly dividend by about 8% and said it will split its stock 7-for-1 in June. At the time, Mr. Icahn said he agreed completely with Apple's plans to boost its buyback plan and said he is "extremely pleased" with the company's quarterly results. He also said the stock "remains meaningfully undervalued" and that "many analysts fail to understand the company."

Mr. Icahn gave up his fight in February to force Apple to boost its share-repurchase program by $50 billion. Before that, he had retreated from a demand that the consumer-technology giant load up on debt to fund a buyback three times that size.

As for Netflix, the filing showed that Mr. Icahn continued to decrease his holdings, leaving him with 2.2 million shares at the end of March. High-growth and momentum stocks such as Netflix have tumbled in recent weeks. Shares of Netflix have declined around 21% over the past three months.

(By Polya Lesova)

Berskshire Hathaway

Warren Buffett's Berkshire Hathaway Inc. (BRKA) bought 11 million shares of Verizon Communications (VZ) and reduced its stake in General Motors Co. (GM) and DirecTV (DTV) during the first quarter, according to a regulatory filing.

The Verizon stake was valued at about $524 million as of the end of March. Given the size of the stake, it's likely to be a purchase made by one of Mr. Buffett's two investment managers.

The Omaha, Neb.-based investor has previously said he typically picks the big, multibillion-dollar positions for Berkshire while his managers, Ted Weschler and Todd Combs, buy smaller stakes.

Each of the two managers has over $7 billion to manage in a U.S. portfolio of 45 stocks valued at roughly $106 billion. During the quarter, Berkshire reduced its stake in satellite television company DirecTV, another investment of the duo, by 2 million shares. Berkshire still owns 34.5 million shares of DirecTV, which were valued at $2.6 billion at the end of the first quarter.

The Wall Street Journal has reported that AT&T Inc. (T) is in talks to buy DirecTV for about $50 billion. At that price, Berkshire stands to make a profit on its holding of the stock.

Berkshire also cut its position in General Motors by 10 million shares, and now owns 30 million shares valued at about $1 billion.

The company increased its stake in International Business Machines Corp. (IBM) slightly. IBM, along with Wells Fargo & Co. (WFC), Coca-Cola Co. (KO) and American Express (AXP), are Mr. Buffett's "Big Four" stocks, collectively worth more than $60 billion.

(By Anupreeta Das)

Soros Fund Management

Soros Fund Management LLC sold out of holdings in several banking giants in the first quarter, including J.P. Morgan Chase & Co., Bank of America and Citigroup.

The exits come only a quarter after the fund had purchased stakes in J.P. Morgan and Citi. In all, the fund had owned about 2.8 million shares of J.P. Morgan as of Dec. 31 and 2.3 million shares of Citi. Shares of both banks are down more than 7% year to date.

The prominent fund also eliminated its stakes in Alcoa and J.C. Penney in the period ended March 31, and decreased its stakes in Liberty Global, Zynga, Microsoft and General Motors. The fund's move with General Motors follows a hard quarter for the car maker, while the decreased stake in Microsoft comes just two quarters after the fund had increased its stake significantly.

The hedge fund, founded by billionaire investor George Soros, increasingly had lowered its stake in J.C. Penney in recent quarters as the retailer looks to revitalize its sales in a fiercely competitive apparel market.

Also in the quarter, Mr. Soros's fund slightly increased its stake in Herbalife, leaving it with 4.9 million shares as of March 31, up from 3.2 million a quarter ago.

Mr. Soros's fund, which disclosed in 2011 it would return cash to outside investors, invests money for Mr. Soros and his family.

Investors who manage more than $100 million are required to disclose most securities holdings within a month and a half of the end of a quarter. The filings give the public a relatively fresh look at the portfolios of well-known investors. The fourth-quarter deadline was Friday.

(By Geoffrey Rogow)

Third Point

Daniel Loeb's hedge-fund Third Point LLC added sizeable new stakes in companies including American Airlines Group Inc. (AAL), AnheusAer-Busch InBev NV (BUD) and Verizon Communications Inc. (VZ), according to a regulatory filing Thursday.

The hedge-fund manager, who recently settled a seven-month-long battle with art auction house Sotheby's (BID), disclosed he held at the end of March 2.7 million shares of American Airlines, 1.4 million shares of Anheuser-Busch and 3.5 million shares of Verizon worth about $166 million.

The New York hedge fund also revealed new stakes in Avago Technologies Ltd. (AVGO), CF Industries Holdings Inc. (CF) and the Industrial Select Sector SPDR Fund (XLI), an exchange-traded fund that ABTprovides exposure to the industrial sector for the S&P500. Its stake in the industrials ETF was worth about $262 million, according to the filing.

Third Point exited positions it held at the end of 2013 in Abbott Laboratories (ABT), BlackBerry Ltd. (BBRY), Gilead Sciences Inc. (GILD) and Yahoo Inc. (YHOO) and increased its stakes in Liberty Global PLC (LBTYA) and Actavis PLC (ACT). Actavis in the first quarter agreed to acquire rival drug maker Forest Laboratories Inc. (FRX).

Third Point had other pharmaceuticals bets, according to the filing, holding a small stake worth about $33 million in Valeant Pharmaceuticals International Inc. (VRX), which had teamed up with hedge-fund manager William Ackman to try to buy Allergan Inc. (AGN). Allergan formally rejected the hostile takeover bid earlier this month.

Third Point decreased its stake in American International Group Inc. (AIG) to 7 million, down from 12.5 million shares at the end of 2013.

(By Juliet Chung)