Semiconductor stocks are dropping Wednesday after Goldman Sachs warned about deteriorating memory chip demand.
The firm lowered its rating to neutral from buy for shares of memory chipmaker Micron.
"We see incrementally weaker demand datapoints combined with accelerating supply growth" in the fourth quarter and in the first half of next year, the firm's analyst, Mark Delaney, said in a note to clients Wednesday. He added the firm now expects "incrementally more DRAM [memory chip] oversupply" in the first half of next year.
Delaney also sees "weaker fundamentals" for the flash memory market.
Micron shares closed down 4.3 percent Wednesday. Other chips stocks such Qualcomm and Analog Devices also ended down 1 percent or more.
Shares of Seagate and Western Digital fell in early trading, but later rallied to close with gains.
Chip stocks are under pressure this month due to heightened concerns about slowing memory chip demand.
Last week Morgan Stanley and an executive at KLA-Tencor said the memory chip market is deteriorating versus expectations, which drove a big drop in the semiconductor sector's shares.
Micron's stock is down 17 percent month to date through Tuesday and shares of Western Digital and Seagate are down more than 8 percent in the same time period.