Summary Box: Apple’s stock closes above $600

THE MILESTONE: Apple’s stock rallied in the final minutes of trading to close above $600 for the first time Monday.

THE BACKDROP: It came on the same day the company announced plans to reward shareholders with a dividend and a share buyback program, and a few days after Apple began selling a third version of its iPad tablet computer.

OTHER ACHIEVEMENTS: Apple is the world’s most valuable company. Its market capitalization topped $500 billion for the first time in late February, a market value peak where few companies have ventured.