Become Your Own Arbitrageur  Some say that when Warren Buffett
decided to create his "Baby Berks" class of Berkshire Hathaway
(NYSE: BRK-A  ) (NYSE: BRK-B  ) stock a decade or so ago, he did
it to stop people from divvying shares up on their own.  Unit
investment trusts had planned to buy Berkshire stock -- which
was then trading around $33,000 a share -- and sell units to
small investors who couldn't afford the Class A share price.
Berkshire stock has never been split, and the Class B Baby Berks
have fewer voting rights than the Class A shares. Today, the Big
Berks trade in excess of $109,000 a stub while the Babies go for
around one-30th of that, or about $3,300.  It's just as Buffett
wanted. Holders of Class A shares can convert their stock into
Class B shares at any time, thus limiting the attractiveness of
a unit trust dividing up the shares. Explaining the price
difference a few years ago, Buffett wrote:  "The Class B can
never sell for anything more than a tiny fraction above 1/30th
of the price of A.