NEW YORK (AFP) - The S&P 500 finished at a fresh record on Thursday (April 29) as investors weighed strong earnings and good economic data against concerns equities have little room to rise after a strong run.

After a volatile session in which the index tripped into negative territory at midday, the broad-based S&P 500 ended with a gain of 0.7 per cent at 4,211.47.

The Dow Jones Industrial Average rose 0.7 per cent to finish at 34,060.36, while the tech-rich Nasdaq Composite Index advanced 0.2 per cent to 14,082.55.

Stocks opened solidly higher following blowout earnings from Apple and Facebook as well as the data showing strong US growth in the first quarter and a drop in jobless claims.

But equities lost steam later in the morning.

Briefing.com analyst Patrick O'Hare attributed the weakness to an emerging narrative about "peak" growth, which was reflected in the market's reaction to Apple's report that earnings rose to US$23.6 billion (S$31.3 billion), more than double.

After opening the session solidly higher, Apple finished down 0.1 per cent.

The view is "the numbers are so good you can't get any better," O'Hare said, noting that stocks had rallied heading into earnings period.

While Apple moved sideways, Facebook finished up 7.3 per cent after reporting that its profits in the recently ended quarter nearly doubled to US$9.5 billion on sharp gains in digital advertising.

But Caterpillar fell 2.1 per cent as it warned of potential supply chain problems even as it reported that quarterly earnings jumped 40.1 per cent to US$1.5 billion.

Lyft sank nearly 10 per cent and Uber Technologies plunged 6 per cent after Labor Secretary Marty Walsh told Reuters he believes "gig" workers should be classified as employees and eligible for full benefits. Shares of food-delivery services DoorDash and Grubhub also fell sharply.