A number of big tech firms are set to report earnings this week, and the results presented by Apple, Microsoft, Facebook and Amazon could provide some insight into what’s ahead for the tech industry in 2016. Combined, the four companies have a market cap of $1.53 trillion, so investors will be keeping a close eye on their movements.

A slowdown in the smartphone market will hit manufacturers on their bottom line, said Syed Talha Saleem, an analyst with Credit Suisse. Beyond the phone industry, a sluggish Chinese economy and a strong U.S. dollar also pose a threat to earnings.

It’s not just the big players that will get hit. "For a few printing companies like Xerox [which reports Friday], there might be some headwinds due to a stronger dollar and more competitive printing environment," Saleem said. The strong greenback makes products from U.S. manufacturers more expensive for overseas consumers and businesses.

Apple, which opened at $101.52 on Monday, is in a tight spot. As China’s smartphone industry approaches saturation, the company’s key source of growth is in peril. In the previous quarter, Greater China sales rose 99 percent to $12.5 billion, accounting for nearly a quarter of global company share.

Saleem said that since November, analyst estimates have factored in supply chain reports that Apple is cutting production. "A lot of that has already been baked in," he said. Apple’s stock price has shifted since these supply chain reports have hit the news, which means the stock price has already, to an extent, factored in this production drop.

"Even though this quarter won’t be that great, the valuation is still pretty attractive from a long term perspective," Saleem said.

Analyst consensus places Apple at achieving an EPS of $3.23 in its next earnings report. The company has an average stock price target of $140.37. Apple will report earnings on Tuesday.

Microsoft, which opened at $51.94 on Monday, is set to report earnings Thursday. The company has gone through a major shift away from Windows as its bread and butter, towards a multifaceted company that sells laptops and cloud storage and services. With that in mind, Surface and Azure are key areas of focus.

"We’re past the incredible drag of winding down a phone business that was not working," Avi Greengart, analyst at Current Analysis, said. The company took a $7.6 billion write down relating to the Nokia acquisition last year. "Given that Microsoft has pruned the underperforming areas of the hardware portfolio, we should expect to see some good numbers," he said.

This quarter has been the first holiday season for the Surface Book and Surface Pro 4 since their launch in October, and while it is unlikely Microsoft will break out the two products, the earnings report will give insight into how well the Surface line is doing overall.

Azure is a strong area of growth. In the previous quarter, Azure sales grew 135 percent, while overall server products and cloud service revenue grew 13 percent. "Some of the biggest stable anchors of the company have been its server and tools," Greengart said.

Analyst consensus predicts Microsoft will achieve an EPS of $0.71 in its next earnings report. The company has an average stock price target of $58.35.

Amazon, which opened at $597.99 on Monday, will report earnings Thursday. Since its previous earnings, the company has worked to improve its core offerings with a new Dash Replenishment service auto-ordering household goods and new releases on the Prime Video service.

The company has also begun moving into new, less traditional areas. Early in January, subsidiary Annapurna Labs announced a new platform-on-a-chip suitable for home Wi-Fi routers and network storage systems.

Last quarter, Amazon beat out estimates with $25.4 billion in revenue, placing expectations high for this quarter. Thirty-five firms have given Amazon stock a "buy" rating, with the general consuensus rating Amazon as a buy.

Analyst consensus places Amazon at achieving $1.58 EPS in its next earnings report. The company has an average stock price target of $757.12.

Facebook opened at $98.57 on Monday, and is set to report earnings on Wednesday. Its dominant position in the social media industry means its growth is more a question of how strong, not whether it will grow.

Investors are likely to follow app installs, and any other data Facebook provides on user growth. Instagram, which surpassed Twitter in September 2015 to reach 400 million users, will also be an area of focus. "That [Instagram] is probably going a long way to form sentiment around the company in the stock," Pivotal Research's Brian Wieser said.

Analyst consensus predicts Facebook will achieve an EPS of $0.68 in its next earnings report. The company has an average stock price target of $124.68.