The S&P 500, a broad index of blue-chip stocks, tumbled 6.7% today to its lowest close since 1997.
The Dow Jones Industrial Average dropped 444 points or 5.6% to close at 7,552, blowing past last month's bear-market nadir to its lowest close since 2003.
The Ad Age/Bloomberg Ad Market 50 index of marketer, media and agency stocks fell 4.5% to its lowest point since the index began in 2000.
Stocks sank on more bad economic news -- jobless claims reached their highest level since 1992 -- and as congressional talk of a taxpayer bailout of Detroit was tabled till December.
General Motors Corp. closed at $2.88, up 3.2%. But what a stunning day: The stock plunged this morning to $1.70, its lowest point since the 1930s, only to surge to $4 on speculation on a bailout compromise. GM shares -- and the market -- then tumbled in late afternoon trading as it became clear domestic automakers will have to wait for any handout.
Ford Motor Co. ended the day at $1.35, up 7.1%.
Interpublic Group of Cos. soared 18.4% to $3.09 after JPMorgan issued a report saying worries about the agency firm's exposure to GM, its top client, were overstated. Interpublic yesterday fell to its lowest point since 1986. But Interpublic was today's top AdMarket performer and the S&P's No. 2 gainer.
Worst AdMarket performers: troubled telecom Sprint Nextel (down 27.1%); CBS (down 17.9%); Time Warner (down 13.1%); outdoor ad firm Lamar Advertising, a new AdMarket 50 member, down 11.6%; and General Electric Co. (down 11.1%).
Time Warner is trading at its lowest point since 1998, when the company was known as America Online, before AOL struck its 2000 deal to buy the old Time Warner.