Nasdaq, S&P hit record highs as tech, health stocks rise

The Nasdaq Composite was up 0.48% at 6,374.67

The Nasdaq and the S&P 500 opened at record highs on Wednesday, powered by technology and healthcare stocks, while the Dow was weighed down by a fall in IBM's shares.

IBM fell 3.9 percent after the company's quarterly revenue came in below expectations.

The tech-heavy Nasdaq closed at a record high on Tuesday, helped by a jump in Netflix, with the index posting its longest streak of gains since February 2015.

The S&P tech sector has been the best performing sector this year despite concerns about stretched valuations as investors look for growth sectors immune to policy uncertainties.

"Netflix's strong results has caused money to move to tech stocks in anticipation of stronger earnings," said Adam Sarhan, chief executive officer at 50 Park Investments.

"If the big names such as Alphabet, Facebook, Amazon are able to show growth in an otherwise low-growth environment, then investors will pay for these stocks."

All three big tech names will report results next week.

Microsoft, which reports results on Thursday, was up 0.6 percent and was among the biggest boosts to the S&P and the Nasdaq.

At 9:45 a.m. ET (1345 GMT), the Dow Jones Industrial Average was up 4.76 points, or 0.02 percent, at 21,579.49, the S&P 500 was up 6.35 points, or 0.25 percent, at 2,466.96.

The Nasdaq Composite was up 30.37 points, or 0.48 percent, at 6,374.67.

Eight of the 11 major S&P 500 sectors were higher, with the health index's 0.78 percent rise leading the advancers.

Vertex Pharmaceuticals jumped 25.6 percent after the company reported positive results for its cystic fibrosis treatment. The stock was the biggest boost on the S&P and the Nasdaq.

Investors will continue to focus on quarterly earnings to see if high valuations are justified in the face of mixed economic data, tepid inflation and policy gridlock in Washington.

Analysts estimate an 8.5 percent rise in second-quarter earnings and a 4.7 percent increase in revenue for the S&P 500 companies from a year earlier, according to Thomson Reuters I/B/E/S.

TMobile, Qualcomm and American Express are among the companies that will report results after the bell.

United Continental Holdings was down 3.7 percent, a day after the airline's quarterly results beat expectation but costs rose.

Morgan Stanley rose 3.6 percent after the Wall Street bank reported better-than-expected profit and bond trading revenue declines that were modest compared with arch-rival Goldman Sachs'.

Advancing issues outnumbered decliners on the NYSE by 1,932 to 586. On the Nasdaq, 1,623 issues rose and 645 fell.