Stock markets on Monday plunged from Tokyo to New York to Frankfurt, as the economy suffered a global crisis of confidence driven mainly by fear that the $700 billion bailout of the U.S. financial industry won't be enough to cure its ills.

On a day of extraordinary market gyrations and expressions of concern, the Dow Jones industrial average lost as much as 800 points before regaining some ground. But the benchmark index still closed below the 10,000-point mark for the first time in four years.

It was a day of panic selling around the world, as the global impact of Wall Street's credit crisis became clearer. Experts warned that intensifying pain in Europe and Asia could slam back into a depleted U.S. economy as markets slow for American exports, one of the mainstays of recent growth.

Market analysts talked in terms of experiencing a fire that was getting harder to extinguish the more it spread, while President Bush sought patience as the government revved up the bailout plan. "It's going to take a while to restore confidence in the financial system," Bush said.

The heart of the problem _ banks too stopped-up with problems or fearful to lend _ continued to devastate confidence, gum up businesses and frighten investors not just in the U.S. but across the global economy, leading some to speculate that the Fed might have to cut interest rates to get money flowing.

With an eye on the markets, Washington took action throughout the day. The Federal Reserve said it would significantly boost the amount of cash it loans to commercial banks on an ongoing basis, ultimately making as much as $900 billion available to get banks lending to each other again. The Treasury Department named Neel Kashkari, a former Goldman Sachs executive, to oversee spending of the $700 billion bailout plan, while President Bush's top economic advisers vowed to move "with substantial force on a number of fronts."

Those actions alone were not enough to allay broader fears. What has become clear since the subprime mortgage crisis began, economists say, is that the global financial system can spread bad times just as effectively as good, and that the worst is probably not over yet.

"One of the worrying things at this moment is it feels like we've been suffering this financial crisis a long time. But, arguably, we're only fairly early into the economic downturn that will result from this," said John Bowler, an economist specializing in risk assessment with the Economist Intelligence Unit in London.