Goldman Sachs was given the Federal Reserve's approval to buy back Berkshire's preferred stock in GS.
Berkshire Hathaway acquires Lubrizol for $9.7 billion.
Announces that David Sokol, a Berkshire Hathaway executive, bought thousands of shares of Lubrizol two months before Berkshire announced a $9 billion deal for the company.
Buys 64 million shares (worth $11 billion) of IBM and becomes one of its largest shareholders.