The most important iPhone launch since then: Four key issues in Apple's earnings report next week

Apple will release its first earnings report next week, which could be its most critical since the launch of the iPhone in 2007, given the company's financial warnings and subsequent stock price volatility.

While the company's stock price has largely recovered its losses, investors still have to face many unanswered questions about the company. Here are four key ones.

How will investors cope with the lack of key data?

A key valuation metric for Apple investors in the past has been its hardware sales figures - in the quarter ending in September, Apple sold 46.9 million iPhones.

But Apple announced it would no longer provide that information. Instead, it will provide revenue and profit figures for hardware and its services business, which includes revenue from the App Store and subscription revenue from Apple Music.

Gene Munster, founder of Loup Ventures and a longtime Apple analyst, commented: "Less disclosure is a negative in terms of reporting," "but we support Apple's strategic shift to a more services-based model by aligning its reporting with investor thinking."

Since Apple has never previously provided data such as gross margin for its services business, whatever the final gross margin is could be an important signal for some investors. Munster expects services to have a gross margin of 65% - whatever the final gross margin is, it could provide some clues to investors about which services are driving growth in this area.

How will the new accounting rules affect Apple's services business?

Part of the reason Apple stopped disclosing iPhone unit sales is that its services business is so important that investors need to think about it differently.

Apple's Services segment has been booming, bringing in $10.8 billion in revenue last quarter, and Apple hopes it will account for 60% of its revenue growth over the next five years.

But the Wall Street Journal previously reported that Apple recently made some adjustments to that number in its financial statements that could change the strong performance of Apple's services business. The changes were made due to new revenue recognition rules, but there is confusion about how these rules affect comparisons with old data.

In the last financial report, in order to prove that Apple's service revenue growth rate did not fall by 20% year-on-year, the company deleted a one-time positive of $640 million from the same period last year. By "forcibly" reducing the revenue of the same period last year to $7.9 billion (original value was $8.5 billion), it proved that the service revenue in the just-passed September quarter increased by 27% year-on-year.

The Wall Street Journal quoted analysts as saying that depending on different accounting standards, Apple's service annual growth rate could be as high as 28% or as low as 18%. Given that Apple has been pinning its hopes on its service business, investors will pay close attention to the new disclosures.

Will the Chinese market stabilize?

When Apple lowered its financial expectations, CEO Tim Cook attributed poor iPhone sales to market weakness in Greater China.

In an interview with CNBC, Tim Cook said he noticed that the Chinese market began to slow down in the second half of last year, but he expected the decline to be temporary and he expressed optimism about it.

But many investors viewed Apple's revenue warning as a canary in the coal mine, arguing that other U.S. companies were also affected amid the global trade dispute.

Investors will be watching closely for any comments from Cook or Apple Chief Financial Officer Luca Maestri to see if they think demand for iPhones in China is about to improve.

Did Apple's "sneaky" price-cutting strategy work?

As signs emerged that Apple might be having a weak holiday quarter, people noticed that the company appeared to be launching new promotions to lower the prices of iPhones.

Apple traditionally doesn't offer discounts, especially on new models that were launched just a few months ago.

So Apple started advertising trade-in deals where consumers could return their old phone and, if it was worth a lot, get an iPhone XR for $450 instead of its retail price of $750.

The question for investors is whether trade-in deals are a reliable way for Apple to increase demand for its flagship products.

If the strategy is successful, investors can expect Apple to continue offering different price ranges through trade-ins, which has the potential to make the growth in trade-in value permanent.

If not, it could be a sign that Apple is losing its ability to price higher than its competitors.