Forget Matteo Renzi and Emmanuel Macron, who both became European heads of state in their 40s.

The Continent may be on the verge of yet another "youth-quake" moment: a millennial prime minister.

Luigi Di Maio is 31 years old, and he could become Italy's next leader when the election is held in 2018.

A lawyer, journalist and former website designer, Di Maio became deputy speaker of the Italian Parliament at the age of 26, the youngest person ever to hold the office.

He is now the candidate of the Five Star Movement and currently leads in the polls with roughly 28 percent of the vote. Markets will likely start reacting this winter if the party continues its ascent, for fear of what it means for the euro and the European Union.

The Five Star Movement is a euroskeptic party founded in 2009 by Beppe Grillo, a comedian turned politician. Grillo is sometimes referred to as Italy's Donald Trump and is famous for his tirades against the European Union and the euro.

Investors eye Five Star warily because Grillo voiced support for an Italian referendum on EU membership long before Brexit was even an idea. Analysts note that a leave vote in Italy would be far more consequential than what happened in the U.K., because Italy uses the euro while the U.K. does not. It could be the beginning of the end for the currency.

Although Di Maio is Grillo's protege, he took a much softer stance on the euro in an interview with CNBC during a recent visit to Washington, D.C.

He told us, through a translator, that a referendum on leaving the EU would be "an extreme last resort" that would only happen if they are unable to make changes to EU treaties. He specifically cited immigration from North Africa as having been detrimental to the Italian economy. As in Germany's recent election, polls show immigration is the key issue for many Italian voters.

Di Maio also wants more control of Italian interest rates — something extremely difficult to do unless Italy has its own currency.

Di Maio's softer stance on a referendum isn't the only way he distances himself from Grillo. Unlike the rumpled Grillo, Di Maio always appears in a well-tailored suit.