Apple's business operations are unlikely to be affected by the fact that chief executive Steve Jobs is to take a medical leave of absence for six months, say analysts.
Jobs told staff in an e-mail that his health problems were more complex than he had originally thought.
Apple's share prices dropped 7% on the news in after-hours trading on Wednesday and the stock slipped another 2.3% at the market close on Thursday.
The value of Apple's shares has been falling since August 2008, mainly on speculation about what was causing Jobs to lose weight and look drawn and gaunt.
This is because Jobs is the public face of Apple. He is closely identified with the company's success and any news about his health automatically creates uncertainty.
But, Van Baker, research vice-president at Gartner, said Jobs is not involved in every operational decision and the company could function fine without him.
Although Jobs inspires Apple employees to work hard and produce good products, said Baker, other members of the executive team could step into this role.
Mike McGuire, research vice-president at Gartner, said that assembling a very strong management team is one of the things Jobs seldom gets credit for.
Jobs has handed over his daily duties to chief operating officer Tim Cook, who has been in high-level management positions at Apple since 1998.
Cook is very close to every major strategic decision or effort the company has made, said McGuire.
Other commentators have pointed to historical evidence to support the view that it will be business as usual at Apple while Jobs is away.
Cook also ran the company for two months in 2004 when Jobs took a medical leave of absence while being treated for pancreatic cancer.