IBM's shares experienced their largest single-day decline in nearly six decades, plummeting over 25% and erasing approximately $70 billion from its market valuation. This drastic fall occurred after the company issued a weak revenue outlook for the second quarter, expecting only about $17.2 billion in revenue, which is a mere 1% annual growth and significantly below analysts' expectations of $17.86 billion. Adjusted earnings per share are also projected at $2.93, falling short of Wall Street estimates of $3.02.

The company attributed this downturn to a rapid and unexpected shift in corporate technology spending. CEO Arvind Krishna acknowledged that IBM "faltered" and did not adapt quickly enough as clients reallocated their budgets towards AI infrastructure—such as servers, storage, and memory purchases—and cybersecurity. This prioritization of AI-related hardware and security over traditional enterprise software, particularly in its mainframe business, resulted in missed large deals and dampened demand for IBM's core offerings.

The unexpected warning sent shockwaves through the broader software sector, impacting other major technology companies like Microsoft, Salesforce, ServiceNow, and Intuit, whose shares also declined. Analysts, such as Chris Beauchamp of IG Group, described it as an "ugly moment for IBM and software stocks," raising concerns about how long this shift in spending towards infrastructure and cybersecurity will last and its implications for the software industry's growth model. Investors are now questioning whether AI investment will expand or replace existing software businesses.

IBM has been investing in quantum computing, including a $10 billion commitment to build a large-scale quantum computer by 2029, and expanding its AI partnerships. However, these initiatives are currently in early stages and are not sufficiently large enough to offset the immediate weakness observed in its core software and infrastructure segments. The company's reliance on its software unit, including Red Hat, which helps firms run applications across different cloud providers, has also been affected by this spending reprioritization.