Apple rose 3 percent after striking a deal to bring the iPhone to China Mobile, the world's largest cell phone carrier. Darden, which runs Red Lobster and Olive Garden, rose 6 percent after activist investor Starboard Value took a stake in the company.
The Dow Jones industrial average rose 82 points, or 0.5 percent, to 16,303 points at noon (1700 GMT) Monday. The Standard & Poor's 500 was up 10 points, or 0.6 percent, to 1,829.
The Nasdaq composite rose 37 points, 0.9 percent, to 4,142. U.S. stock trading will close early on Tuesday and remain closed on Wednesday for Christmas.