Forgot the old saying "sell in May and go away" — this is the year to "buy in May, but be prepared to stay," said Kevin Mahn, president and chief investment officer at Hennion and Walsh Asset Management.
A day after hitting an all-time high Thursday, the S&P 500 set another intraday high Friday. The Nasdaq 100 reached its highest level in over 13 years.
"We are in the midst of a secular bull market," Mahn said, noting that secular bull markets have an average length of 14 years. "We're only 4 years into this one."
While Mahn sees more upside in the second half of 2014, he thinks there will be more potential in the international markets than domestic.
However, "so long as you find companies that are growing their earnings [and] trading at a reasonable price, I still think there's room for growth in this market," he told CNBC's "Power Lunch."