Three former Bitmain employees, who worked specifically in their mining pools (AntPool and BTCcom), were the ones who founded Poolin in late 2017. Although this started as a mining pool for altcoins, in July 2018 they decided to make way for bitcoin mining on their platform. Since then, the rise of said pool in terms of its mining power in Bitcoin has been tremendous; so much so that it is currently in the fifth place of the pools that have added the most blocks to this chain during 2019 (more than 2900 blocks).
Today, Poolin's hash rate is 7.4 EH / s, 11.8% of Bitcoin's total hash rate. This places it in third place among the bitcoin mining pools, according to its mining power. The dizzying growth that the pool in question has shown seems to have caught the attention of Bitmain's executives; who sued their three former employees, Poolin founders, for violation of a non-competition agreement that they would have signed before their departure from this company, in 2017. On the other hand the defense alleges that Bitmain initially breached the agreement, failing to pay the agreed compensation with the defendants on time.