Key Takeaways SiriusXM shares rallied Monday after Warren Buffett’s Berkshire Hathaway raised its stake in the satellite radio company.Berkshire Hathaway now holds a stake of nearly one-third in SiriusXM.

Warren Buffett's Berkshire Hathaway continued to increase its stake in SiriusXM, now owning 32% of the New York-based satellite radio company.The Omaha, Nebraska-based conglomerate purchased roughly 3.

This followed Liberty Media's tracking stocks with SiriusXM in early September and a restructuring of Malone's media assets while also spinning out the Atlanta Braves a company in which Berkshire owns stakes.

Warren Buffett's Berkshire Hathaway now has a stake of about 32.5% in Sirius XM’s publicly traded stock, having become the top holder last month.

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

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.