By Dave Lee, North America technology reporter
It may have been the vision of Steve Jobs that hurtled Apple towards this milestone, but it was the business acumen of Tim Cook that tipped them over.
While other tech stocks have struggled, Apple has soared ahead. The surge in its shares has been driven by two key factors.
It is selling fewer iPhones, but by releasing a more expensive version last year, it is making more money per device.
Apple has also diversified the sources of its profits. It now makes about $10bn every three months from services such as selling apps, cloud storage and music streaming.
The firm told investors this week that it expected a very strong end to the year helped, naturally, by the release of yet another new iPhone.
Stock markets are volatile, and a small but growing threat from Chinese smartphone makers might eat into Apple's margins in the coming years.
But no matter what your view of the company and its products, Apple devices have changed the world - and today made financial history as well.