What keeps Apple's stock going up? In the case of the most recent spike, which has taken it to a new closing record of $100.53, there seem to be two causes: a comment by corporate raider Carl Icahn that actually he hasn't sold any of the stock he holds in the company; and a report from stockbrokers Bernstein Research suggesting that an "iWatch" – a wearable Apple computer of some sort – is being prepared for launch.
Which of those two helped push the stock to its new record is debatable, but let's just say that Bernstein is far from the first estimate built around the (still unacknowledged and unannounced) iWatch. Viewed over the long term, Apple's stock has been on a ramp for years. Shockingly, its value has risen faster than Google's since the latter's IPO just under 10 years ago: Google's stock has risen by 1001%, while Apple's has risen by 4,469%.
Of course, since then Apple has introduced the iPhone and the iPad. Google has added its Android software, which dominates on mobile handsets, but no other significant revenue generator. To the question "is Apple really worth that much?" – on the basis that its market capitalisation is around $602bn (£361bn) – some retort "is it worth so little?" Its price-earnings ratio is still below 17, trailing rivals such as Google at 30 and Amazon at 522 and almost identical to Microsoft, portrayed as a mature giant whose best days are behind it.
Certainly, Apple's profits rely heavily on the iPhone. A new, larger version is expected in early September, with many eager buyers expecting to upgrade. The number of smartphone owners worldwide exceeds 2 billion, and while well over a billion use Google's free Android platform, Apple has about 400 million willing to pay top dollar for its phones. And as the worldwide user base continues to grow, so does Apple's potential market. Putting aside the iWatch excitement, the iPhone is Apple's profit motor. And there's no sign of that misfiring yet.