Kioxia Holdings' shares have surged 456% this year, the strongest gain on the benchmark Nikkei 225 index, as the Japanese memory-chip maker prepares to list American depositary shares in the United States. Sebastian Thomas, lead portfolio manager of Voya Investment Management's roughly $14 billion Global Artificial Intelligence strategy, said liquidity rather than the quality of Japanese companies keeps the fund from investing in Japanese equities. The fund has about $5 billion from Japanese investors but currently holds no Japanese stocks. Thomas said Kioxia's planned ADS listing, announced in May, could broaden its investor base and improve trading access, citing South Korea's SK Hynix after its Nasdaq debut in July. Voya's strategy owns SK Hynix and Micron Technology, while researching Kioxia and Advantest. The fund, affiliated with Sumitomo Mitsui DS Asset Management, has generated approximately 600% in cumulative returns since its launch 10 years ago this month, on a pre-tax, distribution-reinvested basis. Its largest position is Nvidia, although its investments also cover companies such as Eli Lilly that are applying AI outside the technology sector.