Politicians were busy in Washington, and on Wall Street, things were anything but calm. Friday in New York began with a now-familiar feeling: dire expectations of what the opening bell would bring after stocks in Asia and Europe plummeted by as much as 10 percent.

Scott Black, president of Delphi Management in Boston, said he had taken to waking up at 3 a.m. to check on foreign markets. When he arose before dawn on Friday, he was distressed. “I am worried,” he said. “I have a fiduciary responsibility to my clients.”

At the open, the Dow Jones industrial average quickly sank nearly 700 points. But suddenly, shares of struggling financial companies surged, the Dow regained all of its losses in less than half an hour, and a cheer went up on the trading floor of the New York Stock Exchange.

By about 10:20, stocks had started to slide again, and President Bush tried to soothe frayed nerves with an appearance at the White House. “This is an anxious time,” he said. “But the American people can be confident in our economic future. We know what the problems are. We have the tools to fix them. And we’re working swiftly to do so.”

If traders were paying attention to the president, it did not show. Over the course of several hours, stocks ground down, with the Dow losing more than 600 points and again falling below the 8,000 mark.

In the afternoon, an investor walked into a Kansas office of the mutual fund company American Century Investments. The woman, who is two years from retirement, was worried about her small business account. She brought her unopened statement to John Leis, a director of personal financial solutions at the company.

“She didn’t have the guts to open it even though she had conservative investments,” Mr. Leis said. “She asked me, ‘How bad is it going to be?’ ” The client was fortunate: her investments, in mostly government-backed bonds, were up 6 percent for the year. But Mr. Leis said the concern about her investments symbolized the fear among many everyday Americans who are watching the financial markets with trepidation.