https://www.pcgamer.com/monster-hunter-world-has-smashed-the-record-for-biggest-japanese-game-launch-on-steam-ever/

Monster Hunter: World is off to a roaring start on PC. Just hours after the game unlocked on Steam, it's crushed the record for the biggest launch of a Japanese game in Steam's history, which Dark Souls 3 set with 129,831 concurrent players in March 2016. Monster Hunter has nearly doubled that, with a peak of 239,779 players today according to Steamcharts, an amazing number for a game that launched on consoles seven months ago. 

There was no preload option for Monster Hunter: World, so that concurrent peak may continue to grow throughout the day as more people download the game. That number has already put Monster Hunter: World on the list of the biggest launches in Steam's history; it's eclipsed No Man's Sky and Civilization 6, and sits below GTA5 and Fallout 4's massive launch day numbers.