Alphabet Stock Suffers Worst-Ever Day, Loses $500 Billion in Value

Google’s parent company, Alphabet (NASDAQ: GOOGL), endured its worst single trading session on record on October 29, 2026. Shares plunged 13.2%, erasing an estimated $500 billion in market value after a Q3 earnings miss reignited Wall Street’s concerns about AI overspending.

Alphabet reported Q3 revenue of $127.6 billion, slightly below analysts’ expectations of $128.2 billion. It was the company’s first top- and bottom-line miss in nearly four years.

Google Cloud delivered impressive growth of 103%, reaching $30.7 billion. However, Search revenue growth of 12% failed to reassure investors, who are increasingly concerned that AI-powered search tools could cannibalize Google’s core business.

Adding to those concerns is Alphabet’s accelerating investment in AI infrastructure:

• Annual capital expenditure is expected to exceed $200 billion in 2026.
• Spending could surpass $300 billion in 2027.
• Alphabet, Microsoft, Meta, and Amazon are projected to spend a combined $700 billion on AI this year, with that figure potentially topping $1 trillion in 2027.

The sell-off also dragged the Nasdaq down 1.66%, while semiconductor stocks fell 2.0%. Investors are increasingly questioning whether the massive wave of AI spending will deliver proportional returns.

Source: CNBC – Alphabet sinks as it holds 2026 capex unchanged