By Michael J. Martinez
The Associated Press

NEW YORK - Optimistic investors bid stocks sharply higher in light trading Monday, buoyed by the strength of the economy and even ignoring a slight rise in oil prices. The Dow Jones Industrial Average rose more than 140 points.

Much of Wall Street's good will was carried over from Friday, when a strong employment report boosted investor confidence. But some analysts, noting that the light volume from last week also continued into Monday, wondered how sustainable the rally was.

"The market seems to be going up because there aren't any sellers around, not because there's a lot of demand. That has a chance to end badly," said Richard Dickson, senior market strategist at Lowry's Research Reports. "Overseas markets are up strongly, and oil's down, and I think what we're seeing is a little bit of a Pavlovian response to that more than anything else."

Investors were also cheered by a $4.85 billion proposed merger in the casino industry. With mergers and acquisitions gaining popularity, investors saw the trend as a sign of a stable, healthy economy.

The Dow gained 148.26, or 1.4 percent, to 10,391.08.

Broader stock indicators were sharply higher.

The gains marked an important transition from May's heavy selloff. The Dow and Nasdaq had their best close since April 27.

The start of trading on the New York Stock Exchange, the Nasdaq Stock Market and the American Stock Exchange was delayed two minutes in a tribute to former President Reagan.

Most U.S. financial markets will be closed Friday for the national day of mourning.