The memory chip sector is trading sharply lower in the pre-market session, likely driven by profit-taking after a significant rally. The move is amplified by news that prominent investor Michael Burry expanded his short position on sector leader Micron (MU). While major players like Samsung and SK Hynix announced massive new supply deals for AI chips, concerns about high valuations and the blockbuster IPO of Chinese competitor CXMT are providing headwinds.