U.S. East Coast and Gulf Coast dockworkers began their first large-scale strike in nearly 50 years on Tuesday, halting the flow of about half the country's ocean shipping, after negotiations for a new labor contract broke down over wages.

JPMorgan estimates the economic loss from the shutdown of every major container port from Houston to Miami and New York-New Jersey will be between $3.8 billion and $4.5 billion per day.

Transportation and warehousing sectors are poised to first feel the pinch, with a broader economic fallout expected if the strike drags on.