Alphabet Shares Tumble 12.6%, Pulling Asian Indices and U.S. Rates Lower

Alphabet's stock fell apart Thursday, and by Friday afternoon its wreckage had reached Tokyo, Seoul and Hong Kong.

The company's Class A shares dropped 12.6% for their worst session since they began trading more than 20 years ago. Alphabet ranks among the largest companies on Wall Street, and its decline dragged the Nasdaq composite down 365.13 points to 26,184.72. The S&P 500 gave up 23.59 points to 7,720.39, its first loss in four days, even as most stocks inside the index advanced. The Dow Jones Industrial Average shed 132.54 points to 52,342.56.

In Tokyo on Friday, the Nikkei 225 fell 2.3% in afternoon trading to 63,155.94. The Bank of Japan ended its two-day policy board meeting by holding its benchmark rate at 1.25%, a decision markets had largely anticipated after the central bank raised the rate last month. The United States has pressed Japan to raise rates, citing the weakening yen. In currency trading, the dollar moved to 157.67 yen from 157.65 yen, while the euro settled at $1.1186 against $1.1181.

Traders have watched chip makers and other AI-linked shares swing on questions about supply, which fed the volatility visible across regional screens. South Korea's Kospi fell close to 4% to 5,701.71 as SK Hynix and Samsung Electronics both slipped. Hong Kong's Hang Seng gained 1.7% to 23,359.06, the Shanghai Composite lost 0.4% to 3,636.60, and Australia's S&P/ASX 200 added 0.2% to 8,908.10.

Bond and energy markets moved as well. The 10-year Treasury yield dropped to 4.94% from 5.05% late Wednesday, after topping 5.30% earlier this month at its highest level since 2002. Benchmark U.S. crude gained 1.15% to $103.17 a barrel, and Brent crude added 1.05% to $116.09.

Trading in Asia continues Friday, with the Bank of Japan's rate decision now on the record and investors weighing the supply questions surrounding AI-related stocks. Yuri Kageyama reported from Tokyo, with Stan Choe contributing from the business desk.