Google parent Alphabet loses $500 billion in market value as AI spending spooks investors

Shares of Google parent Alphabet plunged more than 12% on Thursday, wiping out around $500 billion in market value in one of the biggest single-day losses in stock market history. The sell-off reflected growing investor concerns over the company's escalating artificial intelligence spending, slowing growth in its search advertising business and uncertainty over how quickly its investments will generate returns.The decline marked Alphabet's worst single-day fall on record, exceeding its losses during the Covid-19 pandemic and the 2008 financial crisis, according to CNN. The market value erosion was the second-largest single-day loss recorded by a company, after chipmaker Nvidia lost nearly $600 billion in early 2025.The sharp fall followed Alphabet's quarterly earnings report, released on Wednesday, which showed sales below analysts' expectations. Investors were particularly concerned about the outlook for Google's search advertising business, which has long been a major source of revenue and profit.The company is facing growing competition from artificial intelligence-powered chatbots that allow users to seek information without relying on traditional search results. Investors fear this shift could weaken Google's advertising business if consumers increasingly turn to AI tools, including those developed by competitors, to find answers online.The concern is that the transition could happen faster than Google can adapt its business model. Jed Ellerbroek, portfolio manager at Argent Capital Management, told CNN that the displacement of traditional search could happen “faster than Google can react to it and pivot their business.”AI spending raises questions about returnsAlongside concerns about its core search business, Alphabet's rapidly rising expenditure on AI infrastructure has intensified scrutiny of its financial performance.The company reported $51.4 billion in capital expenditure in the third quarter alone, compared with $91.4 billion for the whole of 2025. The spending includes investments in data centres and computing infrastructure needed to develop and operate AI services.While technology companies are pouring hundreds of billions of dollars into infrastructure to compete in the AI race, investors are increasingly questioning whether the spending will translate into sustainable profits.A key concern for Alphabet is its free cash flow, which measures the cash remaining after operating expenses and capital investments. The company recorded negative free cash flow for a second consecutive quarter, according to CNN. Before this year, Google had not reported a negative figure for any quarter since going public in 2004.Negative free cash flow does not necessarily indicate that a company is unprofitable. However, it means less cash is available after investment spending to fund shareholder returns, including dividends and share buybacks, or to support other business priorities.Alphabet's performance stood in contrast to Microsoft, which reported $18.6 billion in free cash flow for the third quarter despite continuing to invest heavily in AI infrastructure. Microsoft's shares ended Thursday's session largely unchanged, while Alphabet suffered a double-digit decline.“We are now getting to see who is spending rationally on AI and who is not,” Richard Reyle, chief investment officer at Questar Capital Partners, told CNN.Why investors are becoming cautious about AIThe sell-off highlights a broader shift in how markets are evaluating the AI boom. Investors are no longer looking only at the scale of companies' investments or the growth potential of the technology. They are also assessing whether those investments can generate adequate returns, how much cash they consume and whether AI could undermine existing revenue streams.Alphabet is attempting to expand its AI capabilities while defending its dominant search business. Its investments could help it compete in a rapidly changing technology market, but the returns remain uncertain as the industry races to build data centres and secure computing capacity.Even the prospect of future demand from AI companies does not guarantee immediate profitability. Although AI firms are committing to large amounts of computing power, the financial benefits depend on whether demand continues to grow and whether the infrastructure can be monetised at a sufficient scale.Technology companies are also increasingly turning to debt and financial markets to fund their ambitions, raising questions about the sustainability of the industry's capital spending.“Everybody is trying to get through the door at the same time, and it gives people pause,” Ted Mortonson, a technology-focused investment strategist at Baird, told CNN.For Alphabet, the challenge is to demonstrate that its massive AI investments can produce profitable growth without weakening the cash-generating search business that has supported the company for years. Thursday's steep decline suggests investors are demanding clearer evidence of those returns rather than accepting spending growth as a sign of future success.You use AI every day. Now get your AI Quotient. Take the AIQ test.