Here are some of the stocks the Yahoo Finance team will be watching for you today. Precision Castparts (PCP) It's Warren Buffett's biggest deal ever. Buffett's Berkshire Hathaway (BRK-A) is buying the aviation and energy industry parts maker for more than $37 billion. That prices shares of Precision Castparts at a 21% premium from Friday's close. It would be the second mega-merger for Buffett this year. Back in March, Berkshire and 3G Capital orchestrated the marriage of their Heinz brand with Kraft (KHC). In addition, Berkshire Hathaway said after the close on... More