Nvidia's latest gains reflect the U.S. stock market's return to the "AI trade" that fueled massive gains in chip stocks and related tech companies.

SoftBank founder and CEO Masayoshi Son has called Sam Altman’s OpenAI as “the most valuable company in the world” while speaking at a shareholder meeting. He said that the Japanese company is banking majorly on the artificial intelligence (AI) company as it plans investments.

Nvidia reclinched its title as the world's most valuable company for a second time this month. The AI chipmaker's shares rose more than 4% on Wednesday, closing at a record high for the first time since January, following CEO Jensen Huang's remarks at Nvidia's annual investor meeting.