Canada's deadline to sign onto a trade deal between the United States and Mexico is fast approaching. The country has until Friday to join the new NAFTA deal that the U.S. and Mexico struck Wednesday.

"Markets would really, really like a deal," American Enterprise Institute fellow James Pethokoukis told CNBC on Wednesday. "They would quit trying to play scenarios about withdrawing and what that would mean. They want that certainty."

Trade war fears helped drive Thursday, as Wall Street reacted to reports that President Donald Trump would support moving ahead with tariffs on Chinese imports. Here's what five experts had to say about trade and markets ahead of the big NAFTA deadline.