Check out which companies are making headlines before the bell:
Pharmacyclics - AbbVie is buying the cancer drug specialist for $21 billion in cash and stock. The deal is valued at about $261.25 per share, a 13 percent premium for Pharmacyclics shareholders. The stock has been rising in recent days on reports that Johnson & Johnson was on the verge of buying it.
Costco – The warehouse retailer reported quarterly profit of $1.35 per share, 17 cents above estimates. Overall revenue was slightly below estimates, but same-store sales rose a better-than-expected eight percent during the quarter, excluding fuel sales.
Joy Global – The mining equipment maker missed estimates by 11 cents with adjusted quarterly profit of 25 cents per share, amid commodity price weakness. Revenue was below forecasts, as is the company's fiscal 2015 forecast.
Dunkin' Brands – Goldman upgraded Dunkin' to "buy" from "neutral," pointing to increasing sales, better results from its "Perks" loyalty program, and an expected earnings contribution from its new distribution deal for its coffee.
L Brands – The parent company of Victoria's Secret and Bath & Body Works reported a same-store sales increase of six percent for February, above estimates of a 4.9 percent rise.
McDonald's – Piper Jaffray downgraded the stock to "neutral" from "overweight," saying that the stock is appropriately valued after a recent 12 percent increase, and that initiatives to increase sales may work more slowly many expect.
Buckle – A surprise decline in February sales for the teen retailer. Same store sales fell 2.7 percent, well below consensus estimates of a 0.1 percent increase.
General Dynamics – The defense contractor increased its quarterly dividend to 69 cents per share from 62 cents, a rise of 11 percent.
Citigroup – Citi sold its nearly 10 percent stake in Turkey's Akbank for $1.2 billion, as it continues its move to dispose of overseas assets.
Apple – Apple is said to be delaying the start of production for a planned larger iPad, according to reports. Production is now more likely to begin in September, because of supply issues with larger display panels.
Simon Property Group – Simon is mulling a bid for rival mall owner Macerich, according to the Wall Street Journal. Simon hasn't made a formal offer as yet, although it did reveal a 3.6 percent stake in Macerich last year.
Caesars Entertainment – Caesars won court approval to use some of its cash on hand for at least five weeks. Some creditors of the bankrupt casino operator had registered objections to letting Caesars go through with a plan to spend $334 million through April 3.