Analysts said investors were optimistic after Friday’s government report showed a pickup in jobs for the first time in eight months. Motorola Inc. got a boost after announcing it will spin off its semiconductor business.

"It’s very quiet. Motorola has been the best stock of the day, but people are mostly waiting for earnings to come out," said Todd Leone, managing director of equity trading at SG Cowen Securities.

The Dow Jones industrial average closed up 22.67 points, or 0.2 percent, to 9,594.98, having gained 2.8 percent in the previous week. It was the fourth straight day of gains.

The broader markets also closed higher. The Nasdaq composite index gained 12.91 points, or 0.7 percent, to close at 1,893.48, following a weekly advance of 4.9 percent. The Standard & Poor’s 500 index rose 4.50, or 0.4 percent, to close 1,034.35, having risen 0.9 percent last week.

Stocks enjoyed a boost last week after a government report showed that businesses added new jobs in September for the first time since January. But while investors are largely upbeat, many are wondering whether prices are too high.

Third-quarter earnings reports will provide the most solid evidence of whether the economy is really improving, said Joseph Battipaglia, chief investment officer at Ryan Beck & Co. Results should "not just meet expectations, but beat expectations," for the market to move higher, he said.

"It all comes down to getting those numbers," he said.

Among the companies reporting this week are Alcoa Inc. tomorrow, Yahoo! Inc. on Wednesday and General Electric Co. on Friday.

Motorola rose $1.22, or 9.9 percent, to $13.50 after the company said it will make its semiconductor unit a separately traded company to focus on its mobile phone and other businesses.

PeopleSoft Inc. gained 62 cents to $20.43 after the software maker said its third-quarter earnings will come in higher than its previous forecasts.

Knight Trading Group Inc. climbed $1.85, or 15.3 percent, to $13.95 after the securities-trading firm raised its third-quarter forecast, citing an improvement in trading.

Losers included Duane Reade Inc., which fell $3.31, or 19.4 percent, to $13.80, after the drugstore chain lowered its estimates for the third quarter and the year, blaming slow sales.

Advancing issues outnumbered decliners 3 to 2 on the New York Stock Exchange. Volume was light.

The Russell 2000 index, which tracks smaller company stocks, rose 4.45, or 0.9 percent, to 516.73.