Both U.S. and European stocks rallied on the ECB's historic move, which included imposing a negative interest rate of minus 0.10 percent on banks for their deposits and cutting its main interest rate from 0.25 percent to 0.15 percent.
The "baton of central bank easing" being passed from the United States to Europe could extend the market rally, said Jack Ablin, chief investment officer at BMO Private Bank.
"These [European] markets are trading at probably a 15 percent discount to the U.S.," he said. "I think that's where the next leg of this rally is going to go."
However, bear in mind that the euro will likely fall against the dollar, Ablin warned. He believes that fair value for the euro under the ECB's new program is $1.20 or possibly less.
"The best way to play this, as we're doing, is invest in Europe but hedge that currency back to the U.S. dollar because otherwise you are going to take two steps forward and then one step back with a currency that is declining."
Wasif Latif, head of global multi-assets for USAA Investments, has liked Europe for the last two years, largely because of the valuations of global companies tied to the world economy. He's looking to add to that position, but he said it's time to be more selective.
He likes Germany because of its export capabilities and banking sectors, and Italy from its valuation perspective.
—By CNBC's Michelle Fox.