That’s what J.P. Morgan analysts estimate could be the daily cost to the US economy of nearly 50,000 dockworkers going on strike this morning — a stoppage set to affect almost all cargo ports from Maine to Texas. The workers, many of whom work for the United States Maritime Alliance (USMX), are represented by the International Longshoremen’s Association (ILA).

The high cost reflects the potential for disruption to more than a third of US exports and imports, which often ship through the busy terminals of New York, Baltimore, and Houston.

The White House said in a statement on Tuesday that the president is “assessing ways to address potential impacts” of the strike, “if necessary.”