Lingering mysteries from Berkshire's portfolio update

(This is the Warren Buffett Watch newsletter, news and analysis on all things Warren Buffett and Berkshire Hathaway. You can sign up here to receive it every Friday evening in your inbox.) Lingering mysteries from Berkshire's portfolio update The large reduction in the number of stocks in Berkshire Hathaway's equity portfolio that was revealed in last Friday's first quarter 13F SEC filing was perhaps bigger than expected but it wasn't a total surprise. …