https://www.gamespot.com/articles/pubg-becomes-the-biggest-game-on-steam-briefly-sur/1100-6452900/

Playerunknown's Battlegrounds has continued to climb the Steam charts since its launch earlier this year, though there was no telling when it would stall out. It recently passed the 800,000 concurrent players mark, leaving it behind only Dota 2. Today, PUBG eclipsed even Valve's hugely popular MOBA game, making it the most-played game on Steam.