NEW YORK - Stocks edged mostly lower Wednesday, breaking a six-day winning streak, as investors were disappointed by the latest round of earnings from U.S. companies. A surprise drop in sales of new homes also weighed on the market.

The Standard & Poor's 500 index lost 4.16 points, or 0.2 percent, to 1,875.39. The Dow Jones industrial average lost 12.72 points, or 0.1 percent, to 16,501.65. The Nasdaq composite fell 34.49 points, or 0.8 percent, to 4,126.97.

"The market, even with those six days of gains, is still struggling to choose a direction," said Joseph Tanious, a global market strategist with J.P. Morgan Funds.

High-flying biotechnology and Internet stocks were among the hardest hit. Surgical robot maker Intuitive Surgical fell the most in the S&P 500, plunging $48.40, or 12 percent, to $373.93. The company reported a 77 percent drop in first-quarter earnings and sold half as many robots as it did in the same period a year earlier.

The company warned two weeks ago that earnings would come in far below expectations, causing its stock to plummet from an April 3 high of $540.63.

Amgen fell 5 percent after it, too, reported a steep drop in quarterly earnings, missing analysts' expectations.

One bright spot in biotech was Gilead Sciences, which rose $1, or 1.4 percent, to $73.86 after it reported a surge in first-quarter earnings.

Gilead's drug Sovaldi, a new treatment for hepatitis C, had $2.3 billion in sales in the first quarter alone, which beat the record for any drug in its first whole year on the market. Sovaldi has a 90 percent success rate in curing hepatitis C but is priced at $1,000 per pill, or about $84,000 for a typical course of treatment.

AT&T, despite quarterly results that beat analysts' expectations, fell $1.37, or 4 percent, to $34.92. The company reported earnings of 71 cents a share, 1 cent ahead of expectations, and quarterly sales of $32.48 billion, which also beat expectations.

Verizon fell 49 cents, or 1 percent, to $47.43. T-Mobile US lost $1.28, or 3.8 percent, to $29.81.

Boeing rose $3.08, or 2.4 percent, to $130.63. Quarterly earnings beat expectations as commercial jet production increased.