Profile on Lou Simpson, Buffett's Lieutenant

Morningstar has a profile on Lou Simpson. He's been beating the SP500 by 7% each year for a few decades. Lou's core strategy is to buy "growing businesses at value prices."

Simpson repeatedly stressed the importance of understanding the negatives associated with a potential investment or, as he put it, knowing "why not to buy something." This, he felt, was one of the keys to validating a given investment idea, as it confers a much deeper understanding of the underlying businesses concerned.