If you can provide more context—such as where you saw the name or what the video contains—I can give you a more specific answer.
: It might refer to a generic MP4 video file intended for use in MMS (Multimedia Messaging Service). There are best practices for sending video via text, such as keeping the file size under 500 KB to 1 MB for compatibility.
: There is a mention in some gaming "myth" communities (like Roblox's "Grocery Gang") of a group or user associated with a name like market man.mp4 , which might be what you are thinking of if this is related to internet lore.
