The economy is set to slow down in 2019 against 2018, and many investment professionals have said it's time for active stock picking. 

But there's still room for ETFs, especially for small caps stocks. 

The Russel 2,000, one of the main small cap indexes, has an average trailing one-year price-to-earnings ratio of just above 14, far below its historical average of 18. That's the rational for buying small caps from the head of due diligence and investor opinion at PNC Investments, Larry Wasserman. The full interview is right here

If there's such strong return potential in small caps, maybe ETFs that offer investors broad exposure to the class of stocks isn't such a bad idea. "If you're just looking for broad based diversification and small caps and you want to keep these {fees} down, ETFs are certainly great way to do that. They're pretty much invested across the index in all the constituents," Wasserman said. He added, "the fees on the ETFs tend to be significantly lower than their actively managed counterparts." 

Of course, mutual funds, which are actively managed, offer a premium return potential, as the fund managers can pick the real winners and stay away from the losers. The fees and taxes with those funds are more burdensome. 

Here are two small caps in particular that could stage a big rally soon.