Alphabet shares plunged nearly 13% following disappointing quarterly earnings, marking the second-largest single-day market value loss in stock market history. Alphabet's Class A shares closed at $283.82, down 12.64%, wiping approximately $499.8 billion from the company's market capitalization. The results heightened investor concerns about the company's massive spending on artificial intelligence (AI) and slowing growth in its core search advertising business. Google Cloud revenue more than doubled to $30.7 billion, an increase of 103% from a year earlier, exceeding analysts' expectations of $29.2 billion. Could Alphabet's AI spending concerns pressure tech stocks further? No, the sell-off reflects investor worries over capex sustainability, not a direct household cost impact.