3 Essential Metrics for Apple, Inc. Investors to Watch in 2015

As the year comes to a close, Apple investors can look back happily at a 42% gain. But what will 2015 bring for Apple investors? To hopefully gain some insight about the stock's prospects for 2015 and have a framework for judging the tech giant's performance, here are three Apple metrics worth eyeing closely during the year.

Apple Watch sales It's been a while since the tech giant introduced a new product. The last time was in January 2010, when Steve Jobs unveiled the iPad. While there are a lot of uncertainties surrounding how the watch will sell, one thing is clear: In 2015, the Apple Watch will undoubtedly be one of the hottest topics not just for Apple shareholders, but also for the entire tech world. In fact, it wouldn't be an overstatement to say that 2015 could go down in the tech world as the year of the Apple Watch.

Apple Watch. Image source: Apple.

Expectations for the Apple Watch are high, with a consensus analyst estimate for about 23 million of the devices to be sold in the first 12 months of availability. Depending on the average selling price of the device, a figure like this could help boost Apple's revenue by about 6% -- not bad for an entirely new product in its first year.

Predicting first-year sales of a new Apple product, however, has proven to be incredibly difficult. If Apple's previous new product launches prove to be a guide to the future, Cook and Co. could surprise on the upside.

Year-over-year iPhone growth iPhone sales are becoming more important to Apple's quarterly results. Combining the trends of growing iPhone sales and declining iPad sales, iPhone sales are growing as a percentage of revenue. In the company's most recent quarter, iPhone sales accounted for 56% of revenue. In Apple's fiscal Q1, this figure is likely to grow even more.

For Q1, Apple's dependence on iPhone sales will likely work in the company's favor. With the help of large demand for iPhones with larger screens, it's possible that iPhone sales could increase 40% from the year-ago quarter this year.

But, if sales after the holiday season taper off more dramatically than they did in 2014, iPhone year-over-year growth could become a challenge.

Image source: Apple.

Gross profit marginApple's gross profit margin has always been a key metric to watch, and 2015 will certainly be no exception. Apple's pricing power is arguably the best thing the tech giant has going for it. If its pricing power ever begins to slip -- particularly on its iPhone line -- margins could begin to contract, and year-over-year gains in earnings could become difficult.

For now, Apple's year-over-year gross profit margin is trending upward. Consider last quarter, when the company posted a gross profit margin of 38%, up 100 basis points from the 37% gross margin reported in the year-ago quarter. Further, Apple gross profit margin comps have been positive for three quarters in a row after a streak of negative comps that lasted for more than a year. While it looks like this positive trend will continue into the beginning of the company's fiscal 2015, the Street will be eyeing the metric as the year goes on, particularly to see how it is affected by Apple Watch sales.

While there aren't any negative headwinds in sight for Apple's gross profit margin, the stock's pricier valuation means that expectations for the tech giant's profitability are as high as ever.

What other metrics will you be watching?

The article 3 Essential Metrics for Apple, Inc. Investors to Watch in 2015 originally appeared on Fool.com.

Daniel Sparks owns shares of Apple. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.

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