Stock sell-off shakes markets from Wall Street to Asia

Stock sell-off shakes markets from Wall Street to Asia as investors rotated away from record highs toward concerns over soaring valuations and the cost of AI buildout. On Tuesday, the Nasdaq opened 2% lower and the Dow and S&P 500 were also down at the open, after all three US indexes had reached record levels this year. Nasdaq is up 10% for the year, the Dow is up 6% and above 51,000 points, and the S&P 500 is up 7.3%. Economists warned the surge could resemble the dot-com bubble, especially given that seven tech companies make up 30% of the S&P 500. Losses followed Monday’s moves: Alphabet shares fell 5% after high-profile AI researchers left; SpaceX shares dropped 16% after an IPO-driven boost and a reported plan to raise $20 billion in a bond sale. In Asia, South Korea fell 10%, with SK Hynix and Samsung down more than 12%; Japan’s Nikkei 225 closed down 3.5%.