There is no question that an investment in Apple Inc. (AAPL) has been profitable for many people. Since January 2006 AAPL stock has provided a compounded annual return of about 25%, not including dividends.

Most of that phenomenal performance has, of course, been driven by the success of the iconic iPhone, which now comprises about two-thirds of total corporate revenue and the bulk of net income. AAPL has shipped over 800 million devices since 2007, more than a quarter of that just in the last year. By the end of this year the total will probably exceed one billion.

The growing importance of the iPhone is illustrated below:

But all that was in the past. Investors need to focus on what will influence AAPL stock in 2016 (and beyond).

iPhone, iPhone, iPhone

There is no doubt in my mind that the top driver for Apple stock in 2016 will be the iPhone. The device is still critically important even as the company has taken big steps to diversify its business over the last few years by introducing several new product categories.

That, of course, is a blessing and a curse. Many professional analysts and bloggers, based upon supplier channel checks and guidance, have offered a less than enthusiastic outlook, are lowering price targets, and are projecting a first-time-ever contraction in unit shipments.

A report from Credit Suisse indicates that AAPL has cut orders for iPhone components by 10%. Morgan Stanley analyst Katy Huberty estimates a drop of nearly 6% in iPhone shipments this year. However, even with all the bad news floating around, most analysts are still predicting overall growth at the tech giant. Apple has offered positive guidance as well.

In the past Apple CEO Tim Cook has indicated that the supply chain is too complicated to use a handful of suppliers as a proxy for Apple. I agree with this. Ignore the chatter.

One thing is for certain, the today’s earnings call, and the September release of the next version of the device, likely to be called the iPhone 7, might be two of the most important moments for AAPL stock in some time. Many analysts, techies, investors, and potential buyers will be looking for anything that might put a stop to the unending negativity surrounding Apple. The Apple haters will be searching for clues that confirm their narrative that the company is washed up. I’ll be glued to the computer and phone myself this week.

Other Drivers

To a lesser extent there are a few other things that will influence the stock.

Apple has four other product segments (three of which are growing) with over $10B in revenue. Throw out the iPhone and Apple would still outpace rival Alphabet Inc (GOOG, GOOGL), parent company of Google, and nearly outsell Microsoft Corporation (MSFT), on an annual basis.

Although not broken out separately — it’s included in the “Other” category — the Apple Watch will be heavily scrutinized. Analysts and pundits have been trying to gauge sales of the smart wearable, introduced last spring and likely to be updated this year. Widely differing estimates, some with nothing to back it up, have been flying around. AAPL, citing competitive advantage issues, has refused to provide any sales data. Untethering it from the iPhone is probably on the agenda this time around. And more apps will become available over time.

In the eyes of some, the iPad has become a growing concern as unit shipments are now declining after getting off to a roaring start in 2010. However, it is not just an Apple problem, The entire tablet market is slowing down for a multitude of reasons, including the proliferation of smartphones with larger displays and a generally longer update cycle. AAPL addressed that last year by releasing the iPad Pro which has a screen size approaching that of some notebook computers. The iPad will remain an important part of the Apple story.

A bright spot to report is that even with the entire PC industry struggling, Mac sales are still growing.

Investor Takeaway

While it is usually impossible to accurately predict what will happen in the short term with any stock, it is probably safe to say that in the case of Apple and today’s earnings call, in particular what the company has to say about the iPhone, and the release of a new version in September, will go a long way towards determining the direction of the stock for the rest of the year.

Even if there is even a hint of bad news it still doesn’t mean that AAPL stock isn’t worth a buy. Those still believing in the Apple culture, “think different”, and its widely popular ecosystems, iOS and Mac OS, might want to just hang on.

Disclaimer: The author owns Apple, Inc. stock.