Warren Buffett has owned a lot of stocks during his career, but there's been one position that's consistently outperformed.

Buffett learned from Benjamin Graham, the "father of value investing." He remains a value investor at heart despite straying from Graham's philosophy somewhat over time. Buffett would never buy a stock if he didn't think its valuation was attractive. He undoubtedly thinks the price is right with Sirius XM.

If Berkshire drops its stake under 10%, it will no longer have to file with the SEC for any changes in its Bank of America holding within two business days. Berkshire would have t