Four of the biggest U.S. technology companies face a critical test his week when they release their latest earnings, with investors watching closely for signs of weakness amid broader concerns about slowing U.S. and global economic growth.

Apple, which kicks things off on Tuesday, has perhaps the most at stake. The tech giant shocked Wall Street earlier this month when CEO Tim Cook warned of weaker sales of iPhones, iPads and Macs in China. Apple shares tumbled nearly 10 percent immediately after the Jan. 2 announcement and have yet to fully recover.

"Apple numbers will be a big deal and have an outsized impact on the tech sector and potentially overall markets," said Tony Roth, chief investment officer at Wilmington Trust Investment, in a report.

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Also on the docket: Facebook and Microsoft, which are scheduled to post their results on Wednesday, and Amazon, which reports its earnings on Thursday. Shares of all four tech companies edged own Monday as leading stock indexes fell.

Tech stocks helped propel the stock market to record highs last year, but slumped because of slower global demand, rising trade tensions and investor concerns about stricter regulation.

China is growing at its slowest pace since 1990, taking a particular toll on tech and industrial companies that sell goods in the world's second-largest economy. Ongoing trade tensions between China and the U.S. have aggravated the situation.

Facebook is expected to post strong revenues, indicating that investors remain confident in the social media behemoth despite its being racked by data privacy scandals over the past year. The company released a draft charter Monday ahead of its third quarter earnings, announcing an oversight board for content decisions as it continues to grapple with the fallout from the Cambridge Analytica scandal and other privacy concerns.

Microsoft is also expected to show strong results, bolstered by its expanding cloud-computing business. Analyst expectations are also rosier for Amazon after the online retailer posted record revenues for Black Friday, Cyber Monday and the holiday season.