A massive dockworkers strike could impact cargo movement of leading importers operating on the East Coast and Gulf ports, including Walmart (WMT) and General Motors (GM), according to trade data aggregator Import Genius.

A potential strike by workers at more than 30 seaports from Texas to Maine could wreak supply chain havoc in U.S., impacting food supply, medicine, cars and auto parts.

The week on Wall Street began with some trepidation ahead of a heavy flow of economic data coming in the next few days. On the earnings front, Carnival posted a record third quarter. Profits at the cruise ship operator rose 60 percent from a year ago.