Apple’s growth is expected to be driven by sales in China, where January’s launch of the iPhone 4S triggered a near riot in Beijing.
Earlier this year Morgan Stanley analyst Katy Huberty predicted Apple could sell 40m iPhones in China this year.
Apple is also expected to move into the TV market after the launch of its set-top box Apple TV.
In his report, Mr Muster said: ‘The key risk to the Apple story is pace of innovation.
‘While we have not seen anything to make us believe innovation will slow, it is the fundamental barrier that stands between shares at $600 and at $1,000.