Apple briefly topped $1 trillion in market cap, becoming the first U.S. company to do so. In and of itself, it's an arbitrary and not terribly meaningful milestone. But Apple's size really does matter.
The bottom line: A trillion dollars in market cap means Apple has both the cash and stock to buy anything it wants. That will be very important if the company decides to venture further into areas like self-driving cars or video content. (This NYT interactive graphic puts $1 trillion in perspective, showing all the things that amount would buy.)