Japan’s leading foreign exchange official, Atsushi Mimura, expressed concern on Wednesday about the rapid rise in stock market valuations driven by the global artificial intelligence boom.

Speaking at a Bloomberg event in Tokyo, the Vice Finance Minister for International Affairs cautioned that the pace of the rally may be moving too quickly.

“There are growing concerns about whether the current stock market situation might be a bit too rapid and going too far,” Mimura said, noting that policymakers are closely watching how the AI-driven surge is reshaping investor sentiment and asset prices.

His comments come as Japan’s markets, like many others worldwide, have been buoyed by a wave of enthusiasm surrounding artificial intelligence technologies and semiconductor companies. While the boom has pushed indices to record highs, it has also sparked worries that valuations may be outpacing underlying fundamentals.