Top investor reveals how he's up 26% this year

Traders work on the floor of the New York Stock Exchange in New York City.
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Louis Navellier, who is up 26 percent in his "Squawk Box" Platinum Portfolio for 2015, shares his thoughts on where he's putting money to work in the second half.

By using quantitative analysis to find stocks that have strong sales and positive earnings outlooks but moderate price multiples, the investor has been able to trump the S&P's return by more than 20 percent this year.

Below is his investment thesis for the second half.