Worries around the AI trade sparked a selloff in Asian semiconductor shares overnight, and are now putting pressure on some of the largest U.S. chip stocks premarket.

-- Micron shares are down more than 2%

-- Nvidia, Marvell and Sandisk shares also declined

Driving the moves:

The president of CXMT, one of China's biggest memory chip-makers, said at an industry conference in Shanghai that the company is planning to roll out a new type of DRAM chips.

Concerns that this would threaten the leading market positions of South Korean chip giants Samsung Electronics and SK Hynix sent their shares more than 7% and 10% lower, respectively.

Separately, Broadcom CEO Hock Tan said yesterday in Singapore that many AI investors "have no clue what they are investing in," adding that they had "extreme expectations only to find out that it's almost like they are in a casino."