Apple stock took a tumble even though the company made boatloads and boatloads of cash last quarter. Why? Because some investors believe Apple's profitable run has lasted too long and obviously it must eventually come to an end. They saw the reduced growth rate in iPhone sales as a bad omen.
Unfortunately this is not how the world works and it isn't how statistics work. This misguided belief actually has a term and its called the "Gambler's fallacy".
When a product has been such an incredibly huge success (like the iPhone), it is natural for observers to be pessimistic about the company's ability to generate another similar home run hit but... Keep in mind that Apple is supplementing its product revenue with service revenue.
Apple had total revenue of $50B this quarter. Statistica says $6B came from services. Obviously Any other company would love to have a $6B quarterly service business. Apple is working hard to increase its share of the monthly recurring service business, which would complement its fixed-cycle product revenues nicely.
Apple has room for improvement in services like Siri, Apple Music, iCloud online, etc I think Apple maps is a great example of how they can dramatically improve a product if they put their money, people and determination behind it.
I believe (maybe mistakenly), that WWDC will be the launching platform for Apple's push into services. I believe they will challenge Microsoft and Google head-on. Competition is always good for consumers.
So don't fall for the Gambler's fallacy and don't count Apple out just yet. Yes Apple growth slowed slightly compared to last year but this is a blip in the radar of an otherwise healthy, innovative, tech leader.