Check out the companies making headlines before the bell:
Merck – The drugmaker beat estimates by 5 cents a share, with adjusted first-quarter profit of $1.05 per share. Revenue was very slightly below forecasts. Merck's results were powered by strong growth in sales of its cancer drug Keytruda, an it also raised its earnings forecast for the year.
Pfizer – Pfizer reported adjusted quarterly profit of 77 cents per share, beating estimates by 3 cents a share. Revenue was slightly below forecasts, but Pfizer's bottom line benefited from stronger sales of breast cancer drug Ibrance.
Apple – DA Davidson initiated coverage on Apple with a "buy" rating, saying although the company faces challenges, its huge free cash flow allows it both to return increasing amounts of money to shareholders and make strategic acquisitions.
Under Armour – The athletic apparel maker reported a break-even quarter on an adjusted basis, compared to analyst forecasts of a 5 cents per share loss. Revenue beat forecasts, helped by stronger international sales.
Archer-Daniels Midland – The grain processor beat estimates by 18 cents a share, with adjusted quarterly profit of 68 cents per share. Revenue also topped forecasts. The company said market conditions have improved for many of its businesses, and that it is even more confident about 2018 full year performance.
Regeneron Pharmaceuticals, Sanofi – The drug companies announced they would cut the price of the cholesterol drug Praluent for Express Scripts customers, in exchange for greater patient access.
Facebook – Wedbush added Facebook to its "Best Ideas" list, saying the company would weather the controversy surrounding the Cambridge Analytica data breach.
WellCare Health Plans – The health insurer reported adjusted quarterly earnings of $2.47 per share, beating the consensus estimate of $2.02 a share. Revenue was essentially in line. WellCare raised its full-year forecast, based on strong performance across all its business lines.
Akamai Technologies – Akamai reported adjusted quarterly profit of 79 cents per share, 9 cents a share above estimates. Revenue also beat forecasts. The provider of internet content delivery technology saw its results boosted by its push into cloud security.
Texas Roadhouse – Texas Roadhouse matched forecasts with quarterly profit of 76 cents per share, with its revenue slightly above estimates. Comparable-restaurant sales were higher by 4.9 percent at company-owned restaurants and 3.9 percent at franchised locations.
Cognex – Cognex came in 4 cents a share above Street forecasts, with adjusted quarterly profit of 24 cents per share. The maker of machine vision technology saw revenue miss forecasts and it also gave weaker-than-expected full-year guidance.
Tenet Healthcare – Tenet reported an unexpected quarterly profit, with revenue also beating forecasts. The hospital operator also issued strong full-year guidance as it benefited from lower costs and a jump in patient visits.
BP – BP reported its highest quarterly profit in almost four years, helped by a rebound in oil and gas prices and increasing production.
KLX – Boeing will buy the aircraft parts maker for about $3.2 billion in cash, or $63 per share. KLX had said it would review strategic options in December, and The Wall Street Journal had reported last week that a deal was near.
Las Vegas Sands, Wynn Resorts – The casino operators are on watch as gambling revenue in the Chinese territory of Macau rose a better-than-expected 28 percent in April. Gaming revenue in Macau has now risen for 21 consecutive months.
Intel – The chipmaker will receive $380 million from the Israeli government to expand its manufacturing operations in that country, according to Israeli financial newspaper Calcalist.
Citrix Systems – Citrix was added to the "Conviction Buy" list at Goldman Sachs, which notes stronger pricing in the software company's CSS support services offering.
US Foods – US Foods was downgraded to "sector perform" from "outperform" at RBC Capital, which points to overall food distribution industry stagnation.
NutriSystem – NutriSystem earned 9 cents per share for its latest quarter, beating forecasts by 3 cents a share. The diet plan provider also saw revenue come in above estimates. NutriSystem also raised its full-year forecast.
Roku – KeyBanc rates the maker of streaming video devices a "buy" in new coverage, saying it provides a unique platform in the growing streaming video market.