Depending on the context, "gm5" may refer to other entities:

"GM5" is the shorthand for Grandmaster 5 , the fifth tier within the highest competitive rank in Overwatch 2 . Replay files or recordings of matches at this rank are often shared as video files Hardware (iDatalink): The HRN-AV-GM5 Go to product viewer dialog for this item.

It has been linked to a YouTube channel with an unsettling name ("punish babies"), which added to its notoriety in mystery-focused communities.