New York ? The Nasdaq composite index notched its longest-winning streak in more than three years Thursday after strong gains in factory orders and worker productivity fueled investor expectations of a rebounding economy.

Other market indicators also advanced, reaching heights not seen in more than a year.

Buying accelerated in the afternoon despite an unexpected rise in jobless claims. Analysts said investors remained upbeat and were willing to make additional modest bets on the market — particularly in tech stocks — even after several days of rallies.

“It’s hard to doubt the economy is just going to get stronger and stronger,” said Peter Dunay, chief market strategist at Wall Street Access, a New York-based brokerage firm. “Productivity numbers are very positive. Factory orders are picking up. Retail sales continue to be strong.”

The Nasdaq climbed 16.07, or 0.9 percent, to 1,868.97, for a seven-day gain of 104 points. The last time the tech-focused index notched seven straight days of gains was the period ended Feb. 8, 2000; Thursday’s close also was the highest level since March 19, 2002, when the Nasdaq stood at 1,880.87.

The blue chips also rose. The Dow Jones industrial average advanced 19.44, or 0.2 percent, at 9,587.90, for a five-day gain of 254 points. The blue-chip average is at its highest level since June 18, 2002.

And the Standard & Poor’s 500 index rose 1.70, or 0.2 percent, to 1,027.97, for an eight-day gain of nearly 35 points. The last time the index posted an eight-day winning streak was the period ended March 21; Thursday’s close is the highest level since June 18, 2002.