Stocks drifted between small gains and losses in midday trading Friday as investors focused on Europe's debt situation.
Trading was light ahead of the Memorial Day weekend.
The 17 countries that use the euro are struggling over what to do if Greece leaves the union, and how much they should do to try to prevent that.
The Dow Jones industrial average was down 33 points to 12,495 shortly after noon. It has been on a steady slide this month, giving up most of the gains it notched in the first quarter. It's heading for its first losing month since September.
The Standard & Poor's 500 index was up less than a point to 1,321, and the Nasdaq composite also rose less than a point to 2,840.
Facebook, marking its one-week anniversary as a public company, fell 3 percent to $31.91 That's still about 16 percent below its initial pricing of $38. Talbots plunged 38 percent to $1.58 after women's apparel company said a deadline expired without a deal to be acquired by Sycamore Partners.
Trading in European markets was indecisive. Stock indexes fell in France, Germany and Spain, then rose. Greece's ATHEX plunged 3.5 percent. Borrowing rates edged higher for Spain and Italy.
To be sure, Europe's debt problems are nothing new, but Greece's June 17 elections have created a sense of urgency. Investors are watching closely because the country's new leaders will decide whether Greece agrees to the spending cuts that it must swallow if it wants to stay in the euro, or if it goes its own way. Cutting government spending is unpopular in a country where residents have grown used to public-sector largesse.
If Greece left the euro zone, it would revert to its own currency, which would be severely devalued. The country's standard of living would likely worsen dramatically. Greece makes up just 2 percent of the euro zone economy, but its fate would carry ripple effects to other, larger members.
Unnerved traders could dump the bonds of other struggling European countries, such as Spain and Italy. Residents could start to pull money out of banks there, as has been happening in Greece.
The messages emanating from Europe about how to handle the Greek problem were mixed. But the standoffs so far have almost always lasted until the 11th hour.
"Every time you think it's going to fall off a cliff and end very badly, something happens," said Beata Kirr, senior portfolio manager at Bernstein Global Wealth Management in Chicago. "The European Central Bank steps in to buy Italian and Spanish bonds. Or Germany softens its stance on austerity. All of these things have happened when it's past the precipice."
Friday, the head of Germany's central bank said it was an "illusion" to think allowing euro zone countries to borrow money jointly -- a proposal pushed by other countries -- would solve the crisis. In teetering Portugal, the parliament endorsed a budget plan that would set legal limits on government spending. And Spain's market regulator suspended trading of shares in Bankia, a bailed-out bank that is preparing to ask for even more rescue money from the government.
If Europe is investors' biggest worry, Asia might be No. 2. China, the world's second-largest economy, has propped up global financial markets in recent years as other countries slowed. But now, data suggests that China's growth is cooling as well.
Media reports suggested that some of China's biggest banks will miss their annual lending targets for the first time in seven years, and Taiwan lowered its economic growth forecast for the year.
Caterpillar, which relies heavily on demand from China, fell 1 percent.