Though the stock dropped in after-hours trading, some analysts warned investors against overreacting because Jobs' marginal health condition was not a surprise.
"Don't panic, remain calm," said Colin Gillis, an analyst at BGC Partners. "This is not unexpected."
"He clearly has some major health issues going on," Gillis said. But "deteriorating or not deteriorating, chairman is the perfect role for him to continue providing artistic input."
Tim Bajarin, president of Creative Strategies Inc., described Jobs as a pioneer with an unparalleled track record of success.
"He has had more hits than any technology leader I know," Bajarin said. "And in that context, he's got an amazing legacy. You cannot underestimate his importance on our industry and on American business."
Bajarin said what distinguishes Jobs from others in technology is his appreciation for the key role of industrial design and his desire to make technology as easy to use as any other household appliance.
"I've talked to Steve multiple times," Bajarin said. "Whenever I've ever asked him the question of what drives him, it almost always came back to this: Technology is too hard for people and it has been my goal in life to make it easy."
Photos: Steve Jobs and Apple's influence