The shares rose 9.3 percent to $21.01 in New York after earlier climbing as much as 9.9 percent for the biggest intraday gain since Sept. 19. The stock lost 2.5 percent this month through Monday and slid 44 percent last year.
Johnson, Apple’s former retail chief, has eased on his everyday low pricing model after the company’s revenue fell at least 20 percent for the past three quarters. J.C. Penney will hold sales on popular items tied to “key events and holidays.
