Or, at least someone on his investment team is. Buffett's holding company now owns around $2.4 billion in Sirius XM shares, equal to roughly 30% of the total shares outstanding. Buffett's involvement alone is triggering many investors to pay closer attention.

Warren Buffett’s Berkshire Hathaway has spent another $54 million to purchase Sirius XM stock, giving it a stake of more than 35% in the satellite-radio company.

Sirius XM Holdings (NASDAQ: SIRI) has had a roller-coaster past. When the dot-com bubble burst, however, they sank well below the IPO price. How much would a $75 investment during Sirius XM's IPO be worth today?

Sirius XM Holdings (NASDAQ: SIRI) has had a rough time of late, falling nearly 60% in value over the past 12 months. Yet, one of the most famous investors in history has been a keen buyer of the satellite and online radio company's shares.

This was the stock's second consecutive day of gains.

We recently compiled a list of the 6 Undervalued Entertainment Stocks To Buy Right Now. In this article, we are going to take a look at where Sirius XM Holdings Inc. (NASDAQ:SIRI) stands against the other undervalued entertainment stocks.

Shares of Sirius XM Holdings, Inc. (SIRI) rose early Tuesday as Warren Buffett-led Berkshire Hathaway, Inc. (BRK-A) (BRK-B) disclosed in a late Monday SEC filing that it has increased its stake in the New York-based broadcasting company.

Warren Buffett’s Berkshire Hathaway (NYSE:BRK.A) (NYSE:BRK.B) has further raised its bet on Sirius XM Holdings (NASDAQ:SIRI), boosting its stake to over 35%, latest regulatory filings show. The conglomerate acquired around 2.