With the second-quarter earnings season winding down, 79 percent of S&P 500 companies have topped estimates.
Mylan's 6.8 percent drop was the most on the benchmark S&P 500 after the drugmaker reported quarterly results and said it was actively evaluating a "wide range of alternatives".
Shares of Apple rose 1 percent, while those of Amazon were up 0.8 percent and Microsoft 0.4 percent.
The Dow slid 149.44 points, or 0.6 per cent. Tech stocks have been at the center of a sharp recovery in the S&P since a market rout in February, driving the index close to its record high.
"When we see the earnings growth in 2018, the multiples are reasonable at that record level", said Art Hogan, chief market strategist at B. Riley FBR in NY.
The number of Americans filing for unemployment benefits unexpectedly fell last week, suggesting that a strong economy was helping the labor market counter ongoing trade tensions.
"There is low volatility in the markets as the S&P and Nasdaq are just below all-time record highs, and it seems like markets are complacent right now. You have banks losing because the 10-year U.S. Treasury (yield) came down". The Nasdaq Composite Index increased 3.46 points, or 0.04 percent, to 7,891.78.
Sinclair dropped 4 percent after Tribune Media ended its $3.9 billion deal to be acquired by Sinclair and filed suit.
At 9:53 a.m. EDT the Dow Jones Industrial Average was down 38.77 points, or 0.15 percent, at 25,590.14, the S&P 500 was down 2.83 points, or 0.10 percent, at 2,855.62 and the Nasdaq Composite was down 7.72 points, or 0.10 percent, at 7,875.95.
Declining issues outnumbered advancing ones on the NYSE by a 2.12-to-1 ratio; on Nasdaq, a 1.47-to-1 ratio favored decliners.