Japan’s largest tech fund says AI stocks are not in a bubble and have room to rise further.

The AI market is "just entering its second act,” said Yasuyuki Fukuda, chief portfolio manager of Nomura Asset Management’s Japanese Information Electronics equity fund, and "not at the bubble stage.”

Concerns have been brewing over the global AI boom that has pushed the market capitalization of the U.S. chip giant Nvidia past the $5 trillion mark, the highest valuation ever for a company. With seven large tech companies now accounting for more than one-third of the S&P 500 index’s weighting, investors are asking if this is a sign of overheating, foreshadowing a possible burst of an asset bubble.