Purple Chips

If a company has performed well in the past, there's a good chance it will do well in the future. Naturally, those companies often get chosen by investors as stock market picks.

But a new book argues average investors have a hard time picking out the merely good from the great - and that a relatively simple examination can help you distinguish high-performing purple chip stocks from mere blue chip investments.

David Gray spoke with John Schwinghammer. He's the author of Purple Chips.