(Reuters) - Top U.S. hedge fund management firms, including Soros Fund Management LLC and Viking Global Investors, placed new bets on Netflix Inc (>> Netflix, Inc.) while Tiger Global Management increased its stake in the video streaming company during the third quarter, regulatory filings showed on Monday.

Viking bought 4.5 million shares while Tiger Global upped its stake by 15.43 million shares to 18 million. Soros said it owned 317,534 Netflix shares worth $32.79 million as of Sept. 30.

Investors appear to be moving into Netflix as a hedge against the cable television industry, which is facing increasing threats to revenue as consumers switch to streaming services such as Netflix and Hulu, a trend known as "cord cutting."

Electronic payments provider PayPal Holdings Inc (>> Paypal Holdings Inc) was also a stock darling in the July to September period. Baupost Group LLC took a new stake of 10.9 million shares while Soros took a 4.43 million share stake worth $137.5 million in PayPal.

Billionaire investor activist Carl Icahn showed that he sold his entire stake in e-commerce company eBay Inc (>> eBay Inc) in the third quarter while also reporting a position in PayPal

The actions were revealed in quarterly disclosures of hedge fund manager stock holdings, known as 13F filings, with the U.S. Securities and Exchange Commission. They are of great interest to investors wanting to know what savvy traders are buying and selling.

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 investment opportunities.

The filings do not disclose short positions, or bets that a stock will fall. 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 stakes in the third quarter.

AERCAP HOLDINGS NV

Baupost Group took a new stake of 2.45 million shares.

AKORN INC

Scott Ferguson's Sachem Head Capital Management took a new position in the specialty pharmaceutical company, buying 3.3 million shares.

ALCOA INC

Baupost Group took a new stake of 52.27 mln shares

ALIBABA GROUP HOLDING LTD

Viking cut its position, selling 3.6 million shares to own 2.5 million at the end of the quarter. Blue Ridge adds to its position with 610,000 shares, raising its holdings to 2.4 million shares.

AMAZON.COM INC

Tiger Global increased its stake by 2.45 mln shares to 3.19 million shares in the online retailer while Soros took a 77,877 share stake worth $39.9 million.

AMGEN INC

Alex Denner's Sarissa Capital Management cut its stake in the biotech company, selling 118,000 shares to own 200,000 shares.

BROADCOM CORP

Viking took a new position in the semiconductor company, buying 23.5 million shares.

GENERAL MOTORS CO

David Einhorn's Greenlight Capital Inc increased its share stake in shares of automaker GM by 11.3 percent to 16.3 million shares.

HORIZON PHARMA PLC

HealthCor Management liquidated its position in the specialty pharmaceutical company, selling 3.2 million shares.

MICRON TECHNOLOGY INC

Baupost Group cut its stake in the semiconductor company by 18.7 million shares, leaving it at 1 million shares.

PFIZER INC

HealthCor took a new stake in the drug giant, which makes Viagra, buying 2.7 million shares.

TEVA PHARMACEUTICAL INDUSTRIES LTD

Viking bought into the Israeli pharmaceutical company with 8.9 million shares.

UNITED RENTALS INC

Marcato Capital Management bought 2 million shares in the rental company, establishing a new position in the stock the firm had owned previously a few years ago.

YAHOO INC

Canyon Capital Advisors bought 1.9 million shares in the internet firm, raising its holding to 5.7 million shares.

ZILLOW GROUP INC

Tiger Global sold its entire stake of 3.58 mln class A shares in the online real estate firm.

(Reporting By Jennifer Ablan, Sam Forgione and Svea Herbst-Bayliss; Editing by Bill Rigby)

By Jennifer Ablan