Shares of Charlie Munger's Wesco Financial spiked as much as 19 percent higher today (Thursday) to $387/share after Warren Buffett's Berkshire Hathaway revealed plans to buy the almost 20 percent of Wesco it doesn't already own.
Munger, Buffett's long-time friend and business partner, is Wesco's Chairman of the Board.
Wesco's independent directors and non-Berkshire shareholders still need to approve the transaction.
Wesco shares have settled back a bit from today's high, but is still up almost 13 percent at $366 as of 1:30p ET today.
Berkshire is proposing to pay Wesco's book valueper share at the time the deal closes. Dow Jones notesthat at the end of the second quarter, book value was around $353 per share, but has probably changed since then. Even so, it appears Wesco's market price was well below its book value at the time of the offer, resulting in today's surge.
The stock is still well below its 52-week high of $416 on March, 10, 2010.