NEW YORK (CNN/Money) - The Dow closed above 9,000 for the first time in more than nine months Wednesday, while the S&P 500 saw its best close in 11 months and the Nasdaq hit its best close in a year, as investors seized on signs of strength in the services sector of the economy.

Year-to-date, the Dow is up 8.4 percent, the S&P 500 is up 12.1 percent and the Nasdaq is up 22.4 percent

With the exception of some potential profit taking after such a big run, there is little in the next few sessions that seems likely to derail the rally.

"It's really impressive. It just keeps going, regardless of what the news is," said Donald Selkin, director of research at Joseph Stevens. "If there is any pullback, it's going to be minor."

A number of elements support continued gains, Selkin said, noting the unusual fact that bonds and stocks are rallying at the same time. Other supportive factors include: the rally in financial stocks -- which plays into an economic recovery; the fact that drug stocks, which had been lagging of late, are finally catching up; the strength in techs; the likelihood that the Federal Reserve will cut interest rates at its next meeting; and the multibillion-dollar tax cut.

Thursday brings economic data on factory orders and weekly jobless claims. April factory orders are expected to show a drop of 1.8 percent after rising 2.2 percent in March, according to a consensus of economists surveyed by Briefing.com. The number of Americans filing new claims for unemployment last week is forecast to show little change from the week before, dropping to 421,000 from 424,000.

However, the number is significant as it is a precursor to Friday's May national unemployment report. The unemployment rate is expected to have risen to 6.1 percent from 6.0 percent in April, and employers are thought to have cut 30,000 jobs from their payrolls after cutting 48,000 in April, according to the consensus estimate of economists polled by Briefing.com.

"Everything is showing improvement except labor," Selkin said, "Even if Friday's unemployment number is weak, people will probably put a positive spin on it and say that it makes it more likely that the Fed will cut rates."

The other big focus for investors Thursday is Intel's mid-quarter update, due out after the close. Intel is one of the Nasdaq's most-heavily weighted stocks and is also a Dow 30 member. As such, what the top chipmaker has to say about demand for its business and for information technology spending overall will likely sway tech trading. (For more details on Intel's update, click here.)

The major indexes all closed higher Wednesday, with the 1.9 percent gain in the Nasdaq composite (up 31.09 to 1634.65, Charts) leading the way, followed closely by gains of 1.5 percent for the S&P 500 (up 14.68 to 986.24, Charts) and 1.3 percent for the Dow Jones industrial average (up 116.03 to 9038.98, Charts).

The market has been able to sustain momentum for nearly three months now, with few signs of exhaustion. Investors have been buying on the hope that an economic recovery will become reality in the second half of the year, and every bit of news suggesting this bet may be right has been greeted with stock buying.

Wednesday's news was that the service sector of the economy, as measured by the Institute for Supply Management's services index, grew much faster in May than economists had expected. The ISM's index advanced to 54.5,compared with 50.7 in April and economists' forecast of 52. Any reading above 50 indicates expansion in the sector.

"The rally is clearly influenced by the ISM number," said Peter Green, market analyst at MKM Partners. "While the market looks good today, we are also getting near the upper end of the trading range, and that's something to look out for." Although surpassing and holding above 9,000 is not really significant technically, Green said, it is important psychologically.

As it stands, the Dow is now at its best since Aug. 22, 2002; the S&P 500 is at its best since July 8, 2002; and the Nasdaq is at its highest level since May 31, 2002.

Of the 30 issues that comprise the Dow industrials, 26 closed higher.

Walt Disney (DIS: up $0.97 to $20.73, Research, Estimates) rose 4.9 percent after CEO Michael Eisner said late Tuesday that advance bookings for the company's theme parks during the summer season were encouraging so far. In response, Credit Suisse First Boston raised its price target on the stock to $27 from $23.

Hewlett-Packard (HPQ: up $0.97 to $21.04, Research, Estimates) shares rose 4.8 percent on a technical bounce as the stock approached a new 52-week high.

Airline stocks rallied following a bullish Goldman Sachs note on the sector overall. AMR (AMR: up $1.58 to $8.60, Research, Estimates) added nearly 20 percent in active trade.

Auto stocks were among the decliners after DaimlerChrysler (DCX: down $0.90 to $30.75, Research, Estimates) lowered its full-year profit forecast late Tuesday due to a $1.17 billion second-quarter loss at its U.S. Chrysler unit. A number of brokerage firms cut earnings forecasts for the company following the news. Also adding to the sector weakness: Credit Suisse cut is forecasts for North American light vehicle production before the opening bell.

Martha Stewart Living Omnimedia (MSO: up $0.48 to $10.00, Research, Estimates) shares gained 5 percent after namesake and CEO Martha Stewart and her broker were indicted on nine counts related to her sale of ImClone stock 18 months ago.

U.S. Treasury bond yields continued to decline, with the 10-year note dropping to 3.29 percent as its price rose 10/32 of a point, still up on Alan Greenspan's comments Tuesday that implied the Federal Reserve is considering a rate cut at its meeting June 24-25.

The dollar declined against the yen but continued to regain strength against the euro.

In key commodities markets, light sweet crude oil fell 62 cents to $30.05 a barrel in New York. Gold fell $2.70 to $363.60 an ounce in New York.