exo (hangul: 엑소) is a boy group of south korea formed by s.m. entertainment in 2011. the group was created in 2011, but at the beginning of 2012 was formed completely. it was previously composed of twelve members, which separated into two sub-groups, exo-k and exo-m, where each subgroup sings songs in either korean or mandarin, respectively. exo gained popularity with the release of their first studio album, entitled "xoxo" (2013), which resulted in successes "wolf" and "growl". "xoxo" obtained great success which was why they gained positive reviews from the public. hence they were awarded a 'disk daesang' at 28th golden disk awards and 'album of the year' in 15th mnet asian music awards. the album sold more than one million copies, what did that exo is the south korean artist with more sales than any other within a period of twelve years. their third mini-album called overdose (2014), positioned at the top of the "billboard" 200. exo was later named as the most influential celebrity of korea throughout 2014 by forbes korea. in 2015, exo broke the record that they had before the release of their second studio album, "exodus" (2015), led successfully to exo as the group of male k-pop with the highest position on "billboard" 200 albums lists, as well as a k-pop album with the highest sales in the first week. the first single "call me baby" has also demonstrated its success to become the first songs of k-pop and the only one that got lists of canadian hot 100. with sales figures of "exodus", which surpassed 1 million copies, exo also earned the nickname of "double million seller". their fourth mini-album, "sing for you" (2015), earned a record in its first week of sales getting sell more than 267,900 copies. from 2016, exo returns to grant as the celebrity most influential in 2015 by forbes korea. in may 2014, kris filed a lawsuit against s.m. entertainment to terminate its contract with the agency. luhan also made a demand in november 2014, with the same goal. in april 2015, tao ended their activities with exo and followed the same steps as kris and luhan in august 2015. following the departure of three members, exo is now active with nine members.