US stocks climbed on Thursday as crude oil hit $66 a barrel, reaching a record high for the fourth day in a row and boosting energy companies like Exxon Mobil Corp, while wireless technology company Qualcomm Inc rose on an acquisition.
But technology shares could decline on Friday as Dell Inc gave a weaker-than-expected revenue outlook and its stock dropped 8 percent after hours.
The Dow Jones industrial average rallied 91.48 points, or 0.86 percent, to end at 10,685.89. The Standard & Poor's 500 index gained 8.68 points, or 0.71 percent, to finish at 1,237.81. The technology-laced Nasdaq Composite Index climbed 16.74 points, or 0.78 percent, to close at 2,174.55, putting it marginally higher for the year.
"The market is still being buoyed by the energy sector. I am totally baffled by the fact that the market is ignoring higher energy prices," said Paul Mendelsohn, chief investment strategist at Windham Financial Services. "But at some time, higher energy prices will have an impact."
Shares of Exxon, the world's largest publicly traded company, jumped 1.8 percent, or $1.05, to $60.95 during the regular trading session on the New York Stock Exchange. It was one of the blue chip average's biggest gainers.
And the stock of oil company ConocoPhillips gained 1.2 percent, or 76 cents, to $66.40, helping lift the S&P 500. The American Stock Exchange index of energy companies was up 0.86 percent.
US crude oil futures hit a fresh intraday high for the fourth time this week, climbing to $66 a barrel as traders worried about disruptions in the flow of crude and gasoline supply amid refinery snags, as well as Iran's nuclear activities, which put it at odds with the United Nations' atomic watchdog.
Crude for September delivery rose 90 cents to settle at $65.80 per barrel on the New York Mercantile Exchange, after setting the record.
While higher oil prices are generally considered bad for stocks as they hurt corporate profits and curb consumer spending, they can also increase oil companies' earnings, driving their shares up.
Year to date, the S&P 500 energy sector is up more than 32 percent.
After the closing bell, Dell's stock dropped 8 percent to $36.40 on the Inet electronic brokerage system after its revenue outlook fell short of analysts' expectations. Dell's CEO Kevin Rollins attributed the lower third-quarter revenue forecast to weakness in federal government spending and in the low end of its consumer personal computer business.
The last time Dell's stock fell so much in a single day was September 20, 2001, when it lost 8.3 percent.
Shares of Dell's rivals also slipped in after-hours trading, with Gateway Inc falling 0.8 percent to $3.80 and Hewlett-Packard Co dropping 2.4 percent to $23.60.
During the regular session, shares of media company News Corp rose 3.4 percent, its biggest 1-day percentage gain in nine months, to $18.03, after it reported earnings that topped Wall Street estimates.
McDonald's Corp also helped lift the Dow average, hitting a 4-1/2-year high before closing 6 percent higher at $34.69, as investors snapped up call options on the stock for the second straight day, prompted by market talk that private equity firms may be interested in acquiring a stake in the fast-food restaurant chain for certain real estate assets, according to traders.
Alcoa Inc, also a Dow component, rose 3 percent, or 90 cents, to $29.77 as analysts at brokerage UBS raised the investment rating on the world's largest aluminium producer to "buy" from "neutral."
Qualcomm Inc was the Nasdaq's biggest gainer, rising 3.2 percent, or $1.27, to $40.48 after the supplier of wireless chips and technology licenses said it would buy Flarion Technologies to expand its wireless technology portfolio.