Stock Market Live November 18: S&P 500 (VOO) Opens Lower as Google CEO Warns of an AI Selloff

Market Overview - The Vanguard S&P 500 ETF (NYSEMKT: VOO) experienced a decline of nearly 1% on Monday and continued to slide down another 0.4% in premarket trading on Tuesday, attributed to investor concerns over an overheated market and overpriced AI stocks [2] - Notable declines were observed in AI stocks such as Palantir (Nasdaq: PLTR) and Nvidia (Nasdaq: NVDA), despite Palantir reporting strong earnings earlier this month [2] Company Insights - Alphabet (Nasdaq: GOOG) CEO Sundar Pichai noted the "extraordinary" momentum behind AI stocks this year but expressed concerns about "irrationality" in their valuations, suggesting that no company, including Alphabet, would be immune to potential market corrections [3][8] - Despite the market concerns, Alphabet's stock rose over 1% in premarket trading, contrasting with declines in Palantir and Nvidia [3] Earnings Reports - Home Depot (NYSE: HD) reported Q3 earnings of $3.74 per share on sales of $41.4 billion, slightly missing expectations for earnings but beating sales forecasts. The company projected a sales growth of about 3% for the full year, with net profit expected to decline by 6% to approximately $14.01 per share [4][8] - Home Depot's stock fell more than 4% in premarket trading following the earnings report [5] - Medtronic (NYSE: MDT) exceeded earnings expectations with fiscal Q2 2026 earnings of $1.36 per share and sales of $9 billion, leading to a nearly 4% increase in its stock price [5]