Billionaire Bill Ackman has completely cashed out of his stake in animal health company Zoetis (ZTS) - Get Zoetis, Inc. (ZTS) Report , instead making a big bet on fast food company Chipotle (CMG) - Get Chipotle Mexican Grill, Inc. Report .

Regulatory filings with the Securities and Exchange Commission released on Tuesday reveal Ackman's Pershing Square Capital Management sold off its entire position in Zoetis during the fourth quarter of 2016. The hedge fund had already pared back its investment significantly earlier in the year. Ackman maintains a 2.8-million-stake in Chipotle, where he undertook an activist campaign last year.

The 50-year-old Ackman in December got his way with the burrito maker, adding four new members to its board of directors -- two he chose, two the company did. As part of the deal, Pershing Square agreed not to publicly comment on Chipotle for two years, according to The Wall Street Journal.

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Though he can't say it, Ackman's Chipotle bet is doing well thus far in 2017. The company's stock has climbed more than 12% year-to-date, and at current market price, Pershing's position is worth about $1.2 billion.

Chipotle isn't the only restaurant company Ackman likes.

He has a more than $2.1 billion position in Restaurant Brands International (QSR) - Get Restaurant Brands International Inc Report , parent company to Burger King and Tim Hortons. It's his top holding, comprising about 30% of his public equity holdings as of the end of December. (13F filings, required quarterly from institutional investors by the SEC, are released with a 45-day delay.)

His number-three holding is another food-related company, Mondelez (MDLZ) - Get Mondelez International, Inc. Class A (MDLZ) Report , maker of products including Oreo, Cadbury and Wheat Thins.

This article was written by a staff member of TheStreet.