Wren, who is one of Wall Street's biggest bulls, expects the S&P 500Index to end the year between 2,190 and 2,290. That represents as much as a 9 percent gain from current levels.
He makes the case that the U.S. is the best safe haven play for retail investors, as volatility ramps up in connection with the Brexit vote. Just last week, the CBOE Volatility Index, a popular gauge of market fear known as the VIX, surged to its highest level since February.
"I've argued over the past five years that the U.S. stock market has largely been a safe haven and I continue to believe that," Wren said. Investors "need to be stepping in there. They need to be assertive. They need to stay invested and they don't want to panic on this thing."
Within the large cap sector, Wren singles out consumer discretionary, industrials, technology and healthcare as the the most profitable spots for investors right now.