The Dow Jones industrial average plummeted more than 600 points midday Monday, as the disarray continues following Standard & Poor's downgrading of the United States' credit rating on Friday.

The Dow traded down 536.18 points, or 4.7 percent, at 10908.43. It is fast on track to having its worst day since December 2008. Additionally, the Standard & Poor's 500 index sharply went down 68.49 points, or 5.7 percent, to 1130.89.

Now, worried investors are moving stocks into safer areas such as gold and Treasury bonds, where their confidence still seems to be strong.

Market experts tell the Los Angeles Times that the market selloff on Monday was sparked by the S&P announcement, and is more motivated by growing concerns about the weakness of the global economy.

"It's really all about economics," said Mike Norman, the chief financial strategist at John Thomas Financial, to the paper.

Investors' worry began about two weeks ago during the intense debt ceiling negotiations in Washington. Now that Washington came through, the focus has been shifted on the economic outlook.

Europe's troubled economies of Italy and Spain are also adding to investors' fears, as these countries might need help from the European Union, which already gave assistance to Greece and Ireland.

A financial rescue package for Italy or Spain might be more than the group of countries can handle, according to reports.

"The markets continue to reaffirm our credit as among the world's safest," said President Obama as he tried to reassure the public and markets during a midday speech. "Our challenge is the need to tackle our deficits over the long term. But here's the good news. Our problems are emminently solvable. And we know what we have to do to solve them."