A British exit from the European Union could have dire consequences for the euro, Jurrien Timmer, director of global macro strategy at Fidelity Investments, said Friday.
"I always ask the question: Is this systemic? And I've asked this questions many times with Greece and other developments," he told CNBC's "Squawk on the Street." "The two ways that this could potentially become systemic is that if the U.K. goes, [and] I read that, if the U.K., Scotland will have a new referendum, maybe France or Finland or some other country in the euro will have a referendum."
"It could possibly lead to the end of the euro," he said.
Market concerns about a Brexit have spiked recently with recent polls showing the leave camp had taken a substantial lead over the remain side. However, several experts said that the killing Thursday of MP Jo Cox may give the remain camp some momentum.
"Right now, it looks like a coin toss, and that's certainly not very helpful for either side because, if we're somewhere muddling through the middle, there won't really be a mandate from either the remain or the leave side," Timmer said.
The euro was on track for a slight weekly gain against the dollar in trading Friday afternoon, but not without a choppy ride. The common currency hit its lowest level of the week at about $1.11 on Thursday. Since then, it has surged to about $1.13.
EUR/USD 5-day chartSource: FactSet
U.S. equities, meanwhile, were tracking for a 1 percent weekly loss Friday, as Brexit concerns weighed as well as U.S. economic growth worries.
St. Louis Fed President James Bullard, a hawk on the Federal Open Market Committee, slashed his U.S. economic forecast and said we may only need one small rate hike through 2018.
Vincent Reinhart, chief economist at Standish Mellon Asset Management, said Friday on "Squawk on the Street" this shows him two things.
"One, it's an admission that the Fed is not particularly good at forecasting and drawing a straight line from where we are right now," he said, "Second, it's a very different world view, relative to the more conventional thinking that dominates monetary policy."