Billionaire investor Carl Icahn reduced investments in PayPal Holdings Inc., Nuance Communications Inc. and Freeport-McMoRan Inc., according to a regulatory filing Tuesday.

The New York-based investor also increased his holdings in Herbalife Ltd. and Hertz Global Holdings Inc. in the fourth quarter, and exited Voltari Corp.

He has been increasing his stake in Herbalife in a public feud with hedge fund manager Bill Ackman, who has shorted the distributor of nutrition supplements. All three of Icahn’s energy holdings were unchanged in the fourth quarter, the filing shows.

Billionaire activist investor Carl Icahn
Billionaire activist investor Carl Icahn Bloomberg News

The outspoken investor was named an informal adviser to President Donald Trump in December, after publicly endorsing the real estate executive’s candidacy in September 2015.

Icahn has said he was consulted before Scott Pruitt was nominated to run the U.S. Environmental Protection Agency. Pruitt has criticized the agency’s renewable fuel standard, which Icahn has said could cost one of his companies $200 million. Senate Democrats have asked for more information on Icahn’s role in the administration, given his investments in several industries that are regulated by federal agencies.

Icahn’s publicly traded holding company Icahn Enterprises LP agreed in December to sell its American Railcar Leasing to Sumitomo Mitsui Banking Corp.

Icahn rose to fame in the 1980s as a corporate raider has rebranded as an activist investor and outspoken shareholder advocate. Worth about $20 billion, according to the Bloomberg Billionaires Index, Icahn primarily invests his own fortune rather than relying on money from outsiders.