TradingKey - As of pre-market trading on October 20 Eastern Time, the US memory chip sector weakened again in pre-market trading, giving back gains after Monday's sharp rebound. Micron Technology (MU), SanDisk (SNDK), Western Digital (WDC), and Seagate Technology (STX) all fell in pre-market trading, indicating that the recent adjustment in the memory sector may not be over yet.

Micron pre-market stock price chart, source: FUTUBULL
As of press time, Micron fell about 2.7% pre-market, SanDisk dropped about 3%, Western Digital slipped about 2.7%, and Seagate declined about 2%; SK Hynix's US ADR (SKHY) fell nearly 5%. The pullback in memory stocks coincided with a broader pre-market cooling in AI-related tech stocks, as some capital chose to take profits after yesterday's rapid rebound.
Earlier on Monday, the memory sector saw a strong rebound. SanDisk closed up 5.53%, Western Digital rose 6.09%, Micron gained 2.97%, and Seagate advanced 3.41%, with SanDisk and Western Digital ranking among the top gainers in the S&P 500 Index. The semiconductor sector, which had been falling continuously, also showed a clear recovery, with the Philadelphia Semiconductor Index rising by about 2.4%.
Previously, rising market concerns over AI data center financing costs, capital expenditure sustainability, and technological progress by Chinese memory maker ChangXin Memory Technologies (CXMT) had put continuous pressure on memory stocks. On Monday, a decline in US Treasury yields and a broad rebound in tech stocks brought some low-level buying back into the market, but currently these fundamental concerns have not yet fully dissipated.
Looking ahead, the memory sector will enter a new earnings window. Western Digital will report earnings on October 22, Seagate is expected to release its results on October 27, and SanDisk will report on October 29. The market will focus heavily on AI data center demand, DRAM and NAND price trends, HDD supply and demand, as well as management guidance for the coming quarters.