Wall Street chief stock strategist sees 'historic valuation opportunity' in small-cap stocks for long-term investors

· *Lori Calvasina of RBC Capital Markets told Bloomberg there's a "historic valuation opportunity" in small-cap stocks. *
· *However, the chief US equity strategist said the opportunity should only be for long-term investors with a three- to five-year horizon. *
· *She recommended to everyone to look for the "best in the...