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

Reddit (RDDT) was 3.2% higher in pre-bell hours, after closing Monday with a 6.8% rise.

Advanced Micro Devices (AMD) was up 0.5% in premarket activity, following an 8.8% rise from the previous session.

Palantir Technologies (PLTR) advanced by 0.5% pre-bell, after closing Monday with a 2.9% increase.

Antero Midstream (AM) was 0.4% higher in premarket activity, swinging from a 0.6% decline at Monday's close.

AST SpaceMobile (ASTS) fell by 2.2% premarket, swinging from a 9.2% rise at Monday's close.

Tesla (TSLA) declined by 0.7% premarket, swinging from a 1.2% increase at Monday's close.

Nvidia (NVDA) was 0.2% lower hours before market open, following a 1.9% increase from the previous session.

UnitedHealth Group (UNH) was down 0.2% in pre-bell hours, after closing Monday with a 1.2% decline.