Editor's note: This post originally appeared on Business Insider

Apple (AAPL) is down again today. Apple's been down a lot lately, as you may have heard.

Since it closed above $700 in September, the stock has fallen and can't break out of the $520 range (give or take a few dollars).

What changed at the end of September for Apple that has investors scared?

We, like many others, have thrown out a half dozen different ideas. But, this one from Barclays analyst Ben Reitzes seems to make the most sense. In a note today, he writes the following:

We believe that web services are the next real battleground for Apple and the key for shareholder confidence. One could argue that shares hit an inflection point to the downside when investors realized that the Apple Maps endeavour was a mistake. The maps debacle showed investors how valuable’s Google technology was – how hard it was to replicate – and how Apple may struggle as the world moves beyond iTunes toward cloud-based services.

In non-analyst speak, what he said was Apple's shares got hammered when the severity of the Apple Maps debacle became apparent. And, from a timing perspective, this makes a lot of sense.

Apple released the iPhone 5 on September 21, which was when Apple's stock was peaking. That day the problem with Apple's Maps — which were on the iPhone 5 by default — became a mainstream story. A week later, Tim Cook apologized for Apple's awful maps.

The failure in maps exposed the first truly massive hold in Apple's business. A company that was largely flawless finally had a material flaw. And that flaw gave way to the realization that Apple needs to improve its data and services business.

Since then, we're seen numerous stories talking about how Google is taking over Apple's platform. We've seen a lot of stories about how Apple's software is weaker than third-party software. We've also read about how Dropbox is key to making iOS work.

In short, Apple's design and software problems run deep.

Reitzes argues that Apple will have to prove its Internet services aren't a total mess before investors get back on board with the company:

We believe Apple can turn the tide with a real move into payments, an integrated iOS-led television service and improvements to iCloud (including subscription-based services).

These types of services could re-convince investors that Apple’s ecosystem carries a high switching cost and reinforce the value of an “iOS subscriber.” We believe there is a perception that Amazon and Google are better in web services than Apple – and in order to command more investment dollars – Apple needs to take its innovation in this direction

If this is true, it's very tough for Apple to prove. Any improvements to maps are going to be incremental. They won't suddenly be awesome one day. They'll get better over time.

What investors might want to see is how Jony Ive, Eddy Cue, and Craig Federighi refocus iOS. After Apple's Maps mess, Scott Forstall was tossed out. He may have been a controversial executive at Apple, but aside from Steve Jobs, he's probably the individual most responsible for iOS.

Now the three aforementioned executives have to make iCloud a service that rivals DropBox and Maps that rival Google Maps.

Apple has always been very good at hardware and software, but not data or services. If you're an Apple investor and you're looking for some good news, Reitzes raised his iPhone estimate for he holiday quarter and for the next year. If Apple can sell enough iPhones to beat analysts estimates, investors will probably forget about the Maps problem.