Alex Lane, portfolio manager at Dynamic Funds, says history is on the side of those who are predicting further gains in the U.S. equity market. Data from the past 20-years shows there's a 100% probability of the market moving higher from September through year-end, when the market starts the month with a year-to-date gain of more than 5%. Lane says any weakness over the next couple of months should be viewed as a buying opportunity.