European stock markets fell. France's CAC-40 fell 0.8 percent, Britain's FTSE fell 0.2 percent and Germany's DAX lost 0.4 percent. Insurers such as Munich Re, Aviva PLC and Zurich Insurance fared worse than other stocks as investors worried about the potential cost of the storm's damage.
"The economic impact cannot be underestimated," said Elsa Lignos, an analyst at RBC Capital Markets.
The uncertainty generated by the storm comes at the start of a big week in the United States. This is the last full week before next Tuesday's presidential election and culminates Friday with the release of monthly jobs data, which many analysts think could have an impact on the vote.
"A significant swing in either direction is likely to be heavily reported in the media, potentially swinging the undecided voter," said James Hughes, chief market analyst at Alpari, of the jobs figures.
Some companies are postponing quarterly earnings reports scheduled for release early this week. So far, that includes Pfizer Inc. and Thomson Reuters. Burger King reported on schedule, and said its third-quarter net income fell 83 percent as revenue was hurt by the stronger dollar. Adjusted results topped expectations, however.
Even with many markets shut down, there was some encouraging news about the U.S. economy Monday. The Commerce Department reported that consumer spending increased 0.8 percent in September. That followed a 0.5 percent gain in August and was the best showing since February.
Personal income rose 0.4 percent, an improvement from a slight 0.1 percent gain in August and the best gain since March. It's a closely watched indicator as consumer spending drives about 70 percent of the nation's economic activity.
AP Business Writer Pan Pylas contributed to this story from London.