Seven stocks comprise 82% of S&P's return -analyst

STORY: Added Lynch: "To us, this looks similar to the setup in the post-tech bubble, where you had the same phenomenon running for several years: U.S. large-cap growth tech stocks ate the world. Ate the indices. That blew up in 2000. The next 10 years, what didn't work? Those same concentrated leadership, because their valuations were just too high."