Memory stocks extend Tuesday's gains

Memory chipmaker Western Digital WDC.O rises 3.4% to $279.60 premarket, extending gains from Tuesday when Bernstein upgraded to "outperform"

Peers also extend gains: Seagate Technology STX.O up 2.5%, Sandisk SNDK.O gains 3.4% and Micron Technology MU.O advances 3.3%

Memory stocks sold off last week after Google Research in a blog post announced TurboQuant, a compression algorithm that it says helps AI systems use much less memory without hurting performance

WDC, STX, SNDK and MU have fallen between 8% and 15% since then, as of Tuesday's close

Bernstein says "this however, should have zero impact on HDD demand and negligible impact on NAND demand. Given the stock sell-off we see this as an attractive entry point for STX, WDC and SNDK"

Adds that demand and pricing continue to be better than expected on the back of AI for storage devices

Up to last close, YTD gains are 57% for WDC, 42.3% for STX, 18.4% for MU and 167.6% for SNDK