(Reuters) - Top U.S. hedge fund managers did some shopping for shares of discount retailer Dollar General Corp (>> Dollar General Corp.) and drug store operator Walgreen Co (>> Walgreen Company) in the second quarter.

Daniel Loeb's Third Point added 1 million shares of Dollar General, raising his stake by 33 percent, while Blue Ridge Capital, founded by Tiger Cub John Griffin, nearly doubled its stake in Walgreen when it bought 2.8 million shares. That translated into 4.57 percent of the fund's portfolio.

Other fans of Walgreen included Andreas Halvorsen's Viking Global Investors, which still held more than 20 million shares as of June 30, albeit down from roughly 24 million shares the previous quarter. Aaron Cowen's Suvretta Capital Management had a 312,000 share stake.

Walgreen, which purchased a controlling stake in Britain's Alliance Boots, earlier this month decided not to relocate its corporate headquarters to Europe to save on taxes, a strategy known as inversion. It faced complications in pulling off the transaction, as well as heavy political pressure in the United States not to move.

On Aug. 5, the day before the company said it would not reincorporate in Europe, Walgreen shares traded as high as $72.76. On Thursday, the shares ended regular trading at $62.25.

Billionaire activist investor Carl Icahn, Family Dollar Stores' (>> Family Dollar Stores, Inc.) largest shareholder with a 9.4 percent stake, wanted the company to sell itself to rival Dollar General in the face of stiff competition from big-box retailers such as Wal-Mart Stores Inc (>> Wal-Mart Stores, Inc.). But in July, Family Dollar agreed to sell itself to Dollar Tree Inc (>> Dollar Tree, Inc.).

Meanwhile, David Einhorn's Greenlight Capital reduced its Apple Inc (>> Apple Inc.) stake to about 9.3 million shares, down from about 13.78 million shares, after adjusting for a seven-for-one stock split in June.

Apple long has been one of Einhorn's largest holdings and in a recent conference call, Einhorn said Apple was still "cheap on an absolute basis."

Blue Ridge Capital sold its entire stake, getting rid of 2.2 million shares.

But Leon Cooperman's Omega Advisors took a new stake in Apple of 1.3 million shares, while Soros Fund Management held 1.8 million shares at the end of the second quarter, up from 88,670 shares the previous quarter.

The quarterly disclosures of manager stock holdings, in what are known as 13F filings with the U.S. Securities and Exchange Commission, are always intriguing 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, bets that a stock will fall in price. As a result, the public filings do not always present a complete picture of a manager'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 second quarter.

ALLY FINANCIAL

John Paulson's Paulson & Co took a new 2 million share stake in Ally Financial (>> Ally Financial Inc), and Soros Fund Management opened a new position of 1.5 million shares.

COVIDIEN PLC

Covidien (>> Covidien plc) is being bought by rival Medtronic Inc (>> Medtronic, Inc.) in another inversion deal, in which Medtronic wants to move its headquarters to Ireland to take advantage of lower corporate tax rates.

Farallon opened a new position, buying 2.2 million shares.

DOLLAR GENERAL CORP

While Loeb's Third Point increased its stake in Dollar General, Farallon closed out its position, selling 3.2 million shares, and Omega Advisors sold its entire stake of 1.7 million shares. Tiger Consumer also liquidated its 814,723-share position, which had made up 2 percent of its portfolio.

DOW CHEMICAL CO

Third Point, already a big investor in Dow (>> The Dow Chemical Company), increased its bet dramatically by buying 14.7 million shares, to raise his holdings by 204 percent. The company now ranks as Loeb's biggest U.S. stock holding, at nearly 14 percent of the portfolio.

EBAY INC

Barry Rosenstein's Jana Partners cut its stake in eBay (>> eBay Inc) by 2.9 million shares to 1 million shares.

FACEBOOK INC

Putnam Investments raised its holding in Facebook (>> Facebook Inc) by 30 percent and bought 1.2 million shares. David Tepper's Appaloosa Management held 3.59 million shares as of the end of June 30, up from 478,500 shares as of March 31.

GENERAL MOTORS CO

Tepper's Appaloosa Management increased its stake in GM by 64.7 percent to 13 million shares as of the end of June 30. Putnam Investments increased its stake in GM (>> General Motors Company) by 13 percent when it bought 849,076 shares.

SIRIUS XM HOLDINGS INC

Jana Partners and Eric Mindich's Eton Park Capital Management sold their entire stakes in Sirius (>> Sirius XM Holdings Inc) of 72.3 million shares and 11.2 million shares, respectively.

Omega Advisors cut its stake by 4 million shares to 82 million shares.

SEAWORLD ENTERTAINMENT INC.

Cooperman's Omega Advisors took a new stake of 1.1 million shares in SeaWorld (>> SeaWorld Entertainment Inc), but two sources familiar with the matter told Reuters on Thursday that Omega sold all of its SeaWorld shares "three weeks ago."

Jana Partners, meanwhile, took a new stake of 75,000 shares, while Mindich's Eton Park Capital Management took a new stake of 1.5 million shares.

WALGREEN CO

Stanley Druckenmiller's Duquesne Family Office held its stake in Walgreen's steady at 1.2 million shares, ranking it as the portfolio's third-largest position.

Jana Partners cut its stake by 1 million shares to 11.1 million shares. Third Point added a new position, buying 700,000 shares.

ZYNGA INC

Patrick McCormack's Tiger Consumer Management added a new position in Zynga (>> Zynga Inc), buying 18,062,145 shares.

(Compiled By Jennifer Ablan; Editing by Steve Orlofsky)

By Svea Herbst-Bayliss and Sam Forgione