WALL STREET MAY NOT BE PAVED with gold, but sometimes it sure feels that way, thanks to spectacular winners like Amazon’s stock, Apple’s shares and Bitcoin. The reality: Most investments turn out to be mediocre or worse. Want to notch great long-run gains? Forget trying to pick the winners and instead focus on diversifying broadly. I explain why in my latest article for Creative Planning, where I sit on the advisory board and investment committee.