Shares of South Korean chip heavyweights Samsung Electronics and SK Hynix surged Thursday, a day after the two companies partnered with artificial-intelligence major OpenAI as part of the U.S. firm's Stargate initiative.

Samsung shares hit their highest since January 2021, rising over 4%, while SK Hynix stock surged more than 9% — highest since 2000.

OpenAI said in a statement that this partnership will "focus on increasing the supply of advanced memory chips essential for next-generation AI and expanding data center capacity in Korea."

The ChatGPT-maker said the two South Korean firms plan to scale up production of advanced memory chips, which are critical to power its AI models.

The announcement came as OpenAI CEO Sam Altman met with South Korean President Lee Jae Myung in Seoul, a

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