Remember these words by Warren Buffet....
"We show below our common stock investments. With two exceptions, those that had a market value of more than $700 million at the end of 2006 are itemized. We don't itemize the securities referred to, which have a market value of $1.9 billion, because we continue to buy them. I could, of course, tell you their names. But then I would have to kill you."
It appears that Burlington Northern was one of the two large positions Berkshire was accumulating. Clearly, Berkshire has been a big buyer of Burlington Northern shares since Buffett wrote his letter to shareholders, because Berkshire's position now has a market value of approximately $3.2 billion.
Warren Buffett's Berkshire Hathaway (BRK.B) has disclosed a greater than 10% stake in Burlington Northern Santa Fe (BNI). Through three insurance subsidiaries (Columbia, National Indemnity, and National Fire & Marine) Berkshire beneficially owns 39,027,430 shares of Burlington Northern common stock according to an SEC filing made on Friday, April 6, 2007.
Burlington Northern Santa Fe operates one of the largest rail systems in North America. The system includes 32,000 route miles of track of which 23,000 are owned route miles.
In recent years, Burlington Northern Santa Fe has been buying back stock.