Social Buzz: Wallstreetbets Stocks Mostly Lower Premarket Tuesday; CoreWeave, Nebius Group to Decline

06:39 AM EDT, 10/20/2026 (MT Newswires) -- The most-talked-about stocks in the Reddit subforum Wallstreetbets were mostly lower hours before Tuesday's opening bell. CoreWeave (CRWV) declined by 4.9% in pre-bell activity, after a 0.4% fall at Monday's close. Nebius Group (NBIS) was 4.1% lower premarket, reversing a 2.9% increase from the previous session. Sandisk (SNDK) was down 3.1% pre-bell, after a 5.5% increase from Monday's session. Micron Technology (MU) fell by 2.5% hours before market open, swinging from a nearly 3% rise at Monday's close. Micron's workers union in Taoyuan, Taiwan, will stage a strike on Thursday as the US chipmaker meets with a separate union from its Taichung operations for mediation, Reuters reported, citing a union statement. SpaceX (SPCX) was 1% lower pre-bell, after closing Monday with a 1.3% increase. Meta Platforms (META) fell by 0.9% in pre-bell activity, following a 0.6% decline from the previous session. Tesla (TSLA) was slightly declining in premarket hours, swinging from a 3.8% increase from Monday's session. Bucking the trend, Amazon.com (AMZN) was up 0.3% pre-bell, following a nearly 5% increase at Monday's close.