One is Sirius XM Holdings (NASDAQ: SIRI). While Berkshire has owned the Liberty Media tracking stock since 2016, which tracked Liberty's large stake in Sirius, Berkshire has increased its bet on the satellite radio operator this year, ahead of the tracking stock's merger with publicly traded Sirius shares in a simplification merger in September.

Warren Buffett’s company apparently is taking advantage of the weakness in the stock, which is down 50% this year.

Warren Buffett is amplifying his bet on Sirius XM Holdings Inc., as Berkshire Hathaway Inc. keeps adding more shares of the radio broadcasting firm to its portfolio.

Sirius XM, backed by Berkshire Hathaway, maintains strong market share and high ARPU despite competition from Spotify and Apple Music. Find out why SIRI stock is a Buy.

Warren Buffett has been buying shares of Sirius XM Holdings. Between Oct. 9 and Oct. 11, Berkshire Hathaway purchased an additional 3,564,059 shares of Sirius XM for $86.7 million. This increased its stake in the company to 32.