Alcoa's results are often seen as a harbinger for other major companies. Wall Street forecasts a 1 percent decline in second-quarter earnings of S&P 500 companies compared with last year, according to Standard & Poor's Capital IQ. That would be the first decline since the third quarter of 2009.
Advanced Micro Devices Inc. dropped 6 percent in after-hours trading after the semiconductor company unexpectedly released preliminary results following the market close. Revenue fell 11 percent from the previous quarter due to weak sales in China and Europe. The company had previously forecast revenue growth of 3 percent. The stock slumped 33 cents to $5.29 but was recovering later.
Investors were also spooked Monday by news from Europe, where Spain's borrowing costs rose as finance ministers from the euro countries gathered in Brussels to finalize a rescue package for Spain's banks.
The interest rate on Spain's 10-year government bond rose to 7 percent. Greece, Ireland and Portugal all asked for help from their international lenders when their borrowing costs rose that high.
In Greece, a new three-party coalition government won a vote of confidence in parliament early Monday, ending a period of uncertainty that led to two elections in less than two months. Greece is in its fifth year of recession and has survived for two years on international rescue loans.
Among other stocks making big moves:
LinkedIn Corp., the social networking company, fell $5.88, or 5.4 percent, to $102.98 after reports that Facebook would add a job search feature to its website, which could pose direct competition for LinkedIn.
FTI Consulting Inc., a business advisory company, lost $1.70, or 5.8 percent, to $27.43 after announcing on Friday that it was planning to cut 3 percent of its workforce.
Visa Inc. and MasterCard Inc. fell after an analyst recommended investors sell the stocks because of the global economic slowdown. MasterCard fell $10.36 to $431.27, while Visa fell $1.63 to $123.65.