The most-talked-about stocks in the Reddit subforum Wallstreetbets were mostly lower hours before Tuesday's opening bell.

Opendoor Technologies (OPEN) fell by 3.6% hours before market open, swinging from a 4.2% increase at Friday's close.

Palantir Technologies (PLTR) was 2% lower premarket, after a 0.9% decline from Friday's session.

Nvidia (NVDA) was down 1.5% pre-bell, following a 3.3% fall from the previous session.

Alphabet (GOOG) fell by 0.9% in pre-bell hours, reversing a 0.5% increase from Friday's session.

UnitedHealth Group (UNH) declined by 0.7% premarket, swinging from a 2.5% increase at Friday's close.

Tesla (TSLA) was 0.7% lower in premarket activity, after a 3.5% decline at Friday's close.

DTE Energy (DTE) was down 0.2% pre-bell, swinging from a 0.1% increase at Friday's close.

Alibaba Group Holding (BABA) was up 1.5% in pre-bell hours, after closing Friday with a 12.9% increase.