NEW YORK - The stock market closed out a painful second quarter Wednesday and left investors with heavy losses and far more doubts about the economy than they had just months ago.

Stocks had their worst quarterly performance since the financial crisis. The Standard & Poor's 500 index, considered by many professional investors to be the best measure of the market's health, lost 12 percent, while the Dow Jones industrial average lost nearly 10 percent. Both indexes are at their lows for 2010.

For the first half of the year, the index is down 7.6 percent, its worst first-half showing since the 13.8 percent it loss at the start of 2002.

On the last day of the April-to-June period, the Dow lost 96 points, and all the big indexes were down about 1 percent.

Investors spent much of the quarter repeating the same questions they had a year earlier: Can the economy continue its recovery? Analysts say that the answer most likely is yes but that traders are realizing it won't be easy.

Economist Joel Naroff of Naroff Economic Advisors, of Holland, Pa., says investors are disappointed the economy is not growing as strongly as they had anticipated earlier this year amid talk of a V-shaped recovery, in which the economy rebounds sharply after its big drop. But he thinks investors have sold too much.

"They're thinking, 'Gee, if we're not getting a V-shaped recovery, we'll get a double dip.' They've gone from euphoria to depression," Naroff said. "The reality is somewhere in between."

Sam Stovall, chief investment strategist of U.S. equity research at Standard & Poor's, dates the end of the latest recession to last August. That means the now-complete second quarter is the third full quarter since the recession's end. He noted that stock drops are not uncommon in such a period. In fact, they happened after three of the four recessions before the latest one.

"Investors anticipate what's going to happen [in a recovery], and sometimes they overanticipate," Stovall said. After a couple of quarters pass, investors go through a "reality readjustment."

And apparently they are still not through at that point: Prices also tend to fall in the fourth quarter after recessions end, though Stovall cautions his data are more a curiosity than conclusive.

The quarter's final day included a last-hour sell-off that has become standard operating procedure, especially when a big economic number like the government's June employment report, due out Friday, is imminent.

The Dow fell 96.28, or 0.98 percent, to 9,774.02. The Standard & Poor's 500 index fell 10.53, or 1.01 percent, to 1,030.71, while the Nasdaq composite index fell 25.94, or 1.21 percent, to 2,109.24.

As the third quarter starts, the focus will be on the jobs report, and, in the weeks ahead, companies' second-quarter earnings reports and forecasts for the coming quarters. Disappointments are likely to keep sending stocks lower.

On Wednesday, ADP said private employers added 13,000 jobs in June. That's well short of the forecast of 60,000 from economists polled by Thomson Reuters. The ADP report is often seen as a precursor to the government's monthly jobs report Friday.

The Labor Department report is expected to indicate that employers cut 110,000 jobs in June. However, economists predict most of the loss is tied to the government's laying off temporary workers hired for the 2010 census.

Companies have been slow to add jobs coming out of the recession. Consumer confidence has fallen, and spending has not picked up as investors had hoped because so many people are still out of work.

As investors pulled out of stocks throughout the quarter, U.S. Treasuries and gold were big beneficiaries. The perceived safety of the two helped push bond and gold prices higher.

The Russell 2000 index of smaller companies fell 6.47, or 1.05 percent, to 609.49.

Britain's FTSE 100 edged up 0.1 percent, Germany's DAX index gained 0.2 percent, and France's CAC-40 increased 0.3 percent.