"Negative latency" is a concept by which Stadia can set up a game with a buffer of predicted latency between the server and player, and then use various methods to undercut it. It can run the game at a super-fast framerate so it can act on player inputs earlier, or it can predict a player's button presses. These tricks can help the game feel more responsive, potentially more so than a console game running locally at 30fps with a wireless controller.
https://www.engadget.com/2019/10/10/google-stadia-negative-latency/