Billionaire Barry Rosenstein's Jana Partners submitted its Q4 2017 13F filings to the SEC, and now analysts are poring over the documents to find out how the billionaire investment giant moved his assets and holdings in the final months of last year.

Jana Partners ended 2017 with a total of 43 holdings as reported by its 13F, according to Nasdaq.com. Of those positions, 12 were newly added in the final quarter of the year. Sixteen positions saw an increase over the course of the fourth quarter, while 25 were decreased.

The total of 43 positions also included 14 positions which had been sold out entirely from the previous quarter. Among Rosenstein's most significant purchases for the fourth quarter were Facebook (FB), Comcast (CMCSA), and Teva Pharmaceutical Industries (TEVA).

New Positions in PTC, Facebook and Comcast

Of Rosenstein's 12 new positions for Q4, the largest purchase was for software company PTC Inc. (PTC). Jana bought more than 1.4 million PTC shares over that three-month period.

Facebook was the fourth-largest new buy for Jana Partners, with a total of 473,526 shares purchased as of December 31, 2017.

Comcast followed that, as Jana amassed a stake of more than 2.1 million shares valued at $84 million. The fund bought more than $69 million in Teva stock, accounting for more than 3.5 million shares.

Teva was popular more broadly in the fourth quarter. Warren Buffett's Berkshire Hathaway revealed holdings of more than $300 million in the pharmaceutical company, prompting a quick boost in the stock price upon the release of 13Fs. (See also: Hedge Funds Bet on Consumer Discretionary Stocks: 13F Filings.)

Largest Positions Are EQT and Zimmer

Rosenstein's largest holdings are energy company EQT Corp. (EQT), Zimmer Biomet Holdings (ZBH), and Tiffany & Co (TIF). His firm holds more than $463 million in EQT stock, over $453 million in Zimmer stock, and close to $388 million in Tiffany stock. The 12 new positions added in Q4 do not come close to topping these three leading holdings.

Jana Partners' portfolio is more than 29% weighted toward consumer cyclicals. Industrials stocks make up about one-fifth of its holdings, while energy companies account for about 13%. The total market value of Jana's holdings as of December 31, 2017 was more than $3.5 billion.

Notable sell-offs for the final quarter of 2017 include the investment company Altaba Inc. (AABA). Billionaire Barry Rosenstein sold off shares worth more than $113 million over the course of the final three months of the year, eliminating the position in the process. (See also: Citadel Advisors' Stock Holdings Rose 18.2% In 4Q: 13F.)

13F reports do not provide a full picture of a firm's holdings. Further, they are out of date by the time the reach the public, as they reflect holdings at the end of the previous quarter.