US technology stocks came under heavy selling pressure last week as investors questioned whether the enormous investments in artificial intelligence (AI) infrastructure will generate sufficient returns. The decline comes at a crucial moment for Wall Street, with major technology companies preparing to report their third-quarter earnings.

On Friday, October 16, the Nasdaq Composite fell 2.1% to close at 26,128.13, while the S&P 500 declined 1.1%. The Nasdaq lost approximately 4.5% over the week, marking its sharpest weekly decline since June. Semiconductor companies and businesses connected to AI infrastructure were among those facing significant pressure.

Investor concerns have increasingly shifted from the growth potential of AI to the cost of building and operating the infrastructure required to support it.

AI Spending Faces a Reality Check

Technology companies have committed substantial capital to data centres, advanced processors and computing systems to expand their AI capabilities. Although this investment could create new revenue opportunities, markets are demanding clearer evidence that the spending will translate into sustainable profits.

Financing has also become a growing concern. AI infrastructure requires substantial upfront investment, and some data-centre operators rely heavily on borrowing to fund expansion. Recent weakness in companies such as CoreWeave has highlighted investor concerns about debt levels, financing costs and the ability of infrastructure providers to generate enough cash to meet their obligations.

Higher interest rates could add to these pressures by making borrowing more expensive. At the same time, investors are questioning whether current technology valuations already reflect overly optimistic expectations for future AI growth.

Meta and Tesla Earnings Take Centre Stage

This week's earnings announcements are expected to provide important signals about the direction of the technology sector.

Meta Platforms will be closely watched for updates on AI investment, advertising performance and its outlook for capital expenditure. Investors want to understand whether its AI initiatives are improving business performance enough to justify their growing costs.

Tesla's results will also attract attention as investors assess its automotive business and longer-term ambitions in AI and autonomous driving. Meanwhile, semiconductor companies reporting results this week could provide further insight into demand for the chips and equipment powering AI development. Netflix's earnings will offer a separate perspective on consumer demand and growth in digital entertainment.

Beyond revenue and earnings, management commentary on future spending, operating margins and cash flow could prove decisive. Strong results alone may not be enough to restore confidence if companies signal that investment costs will continue to rise faster than expected returns.

What Investors Should Watch

The technology sector's near-term direction may depend on whether earnings reports can reassure investors that AI investment remains commercially viable. Evidence of stronger AI-related revenue, disciplined spending and sustainable profitability could help stabilise sentiment.

However, disappointing guidance, expanding debt burdens or further increases in capital expenditure without clear financial returns could extend the sell-off.

Market takeaway: Wall Street is entering a pivotal earnings week as investors reassess the cost and profitability of the AI boom. Meta, Tesla and major semiconductor companies will face scrutiny not only over their latest results but also over whether their AI investments can deliver lasting financial returns.