2013 MMOARPG Path of Exile hit peak concurrency in March thanks to its latest patch
A press release out from Grinding Gear Games declares that update 2.6.0 propelled the MMOARPG to a peak online concurrent player count of 112,800 earlier this month, with 65,000 of those playing concurrently through Steam, putting the game behind only Dota 2 and CS:GO during that chunk of time. According to the studio, that makes 2.6.0 the "franchise's largest and most successful to date with a 40-percent increase in the number of players online for the launch."
2.6.0 was big, but it's not even the biggest thing happening to the New Zealand-based game this year: It's got a huge expansion called The Fall of Oriath coming out in 2017. It most recently made headlines for creating a "transparent lockbox" with declared odds for the best stuff inside.