NEW YORK — The stock market closed at a new 18-month high yesterday, with the Dow Jones industrial average briefly touching 11,000 before retreating slightly. The Dow hadn't crossed 11,000 since Sept. 29, 2008, as the worst phase of the financial crisis was beginning.

The gains were driven by fresh signs that the economy continues to recover. Analysts question whether the gains are sustainable since they have come on low volume, indicating many investors are still sitting on the sidelines.

Stocks got a boost after reassuring statements from Greece and the European Central Bank. Major indexes pulled back after Fitch Ratings cut its view on Greece's debt, but quickly recovered.