Higher health stocks and falling oil leave S&P 500 flat

Wall Street had ended mixed on Monday after a rally in Allergan Plc and other healthcare companies offset a decline in energy shares.

Five of 10 S&P sectors ended higher, led by the health sector's 1.13 per cent increase, while energy and materials sectors both tumbled 1.25 per cent.

Allergan surged 5.98 per cent. Teva Pharmaceutical Industries Ltd said it still expected its $40.5 billion acquisition of Allergan's generic drug business to close in June.

Chevron Corp fell 1.48 per cent as US crude prices dropped 2.8 per cent and traders assessed the impact of wildfires on Canada's oil output and a build in inventory.

A bigger-than-expected drop in China's imports and exports in April pointed to weak demand in the world's second-biggest economy and weighed on materials stocks.

Caterpillar dropped 3.52 per cent, weighing the most on the Dow industrials.

Investors remain cautious about corporate earnings. With first-quarter reports almost all in, earnings at S&P 500 companies, on average, fell 5.5 per cent, while revenue was down 1.9 per cent, according to Thomson Reuters I/B/E/S.

“I would give this earnings season a C or C-. While most of the companies were able to step over a greatly reduced bar of expectations, overall sales growth remains disappointing,” said Alan Gayle, senior investment strategist at RidgeWorth Investments in Atlanta, which has $50 billion in assets under management.

The Dow Jones industrial average ended down 0.2 per cent at 17,705.91 points, while the S&P 500 edged up 0.08 per cent to 2,058.69. The Nasdaq Composite added 0.3 per cent to 4,750.21, helped by a 2.45-per cent rally in the Nasdaq biotech index.

After the bell, solar panel company SolarCity, co-founded by technology billionaire Elon Musk, offered a first-quarter report that disappointed investors, sending its stock down 13 per cent.

During the session, Krispy Kreme Doughnuts Inc jumped 24.32 per cent to after agreeing to be taken private for $1.35 billion.

That made investors hungry for other restaurant stocks, including Kona Grill , up 8.18 per cent, and Pollo Loco , up 5.02 per cent.

Shares of Lending Club Corp tumbled 34.93 per cent. The chief executive officer of the world's biggest online lending platform resigned following an internal probe.

Wayfair Inc jumped 10.17 per cent after the online furniture retailer reported first-quarter sales that beat analysts' estimates.

Declining issues outnumbered advancing ones on the New York Stock Exchange by 1,594 to 1,407. On the Nasdaq, 1,486 issues rose and 1,322 fell.

The S&P 500 index showed 33 new 52-week highs and four new lows, while the Nasdaq recorded 47 new highs and 53 new lows.

About 6.8 billion shares changed hands on US exchanges, below the 7.2 billion daily average for the past 20 trading days, according to Thomson Reuters data.