Nikkei 225 Breaks 51,000 for the First Time as AI Stocks Ignite Investor Optimism

Japan’s Nikkei 225 Index surged beyond the 51,000 mark for the first time on Wednesday, fueled by strong investor confidence in artificial intelligence (AI) and semiconductor-related sectors. The tech-heavy benchmark climbed 2.05% to a record 51,249.82 by midday, building on momentum after breaching the psychological 50,000 level earlier this week.

The broader Topix index rose marginally, up less than 0.1%, as a firmer yen curbed gains across non-tech sectors. However, tech and AI-linked shares continued to dominate the rally, driving Japan’s equity market to new highs.

Leading the charge, Advantest Corporation — a key supplier of semiconductor testing equipment — soared more than 20% after raising its full-year profit forecast by 25%, citing robust global demand for AI chips. SoftBank Group, a major player in AI and chip investments, advanced 2.1%, ranking as the second-biggest contributor to the Nikkei’s rise. Semiconductor manufacturer Lasertec also surged 7.8%, further highlighting investor enthusiasm in Japan’s tech sector.

“Stocks such as Advantest and SoftBank are essentially driving the stock market,” said Nomura Securities strategist Wataru Akiyama. “It’s unclear how long this will last. Once the initial wave passes, the upward momentum may ease.”

Meanwhile, global market sentiment was buoyed by AI-related developments in the United States. Nvidia announced plans to build AI supercomputers for the U.S. Energy Department, pushing all three major U.S. stock indexes to record highs. Microsoft shares also jumped following news that the company secured a 27% stake in OpenAI after approving its restructuring into a public benefit corporation.

Despite the rally, 160 stocks on the Nikkei declined versus 65 gainers. Nidec Corp. tumbled 7.3% after being dropped from the index, while SHIFT Inc. fell 5.3%.