The pool's hash power has dropped from 5,000 to barely 20 PH/s. : OKEx’s mining pool has gone from being one of the world’s largest to not mining any new blocks in over two weeks after the firm lost 99.5% of its hash power one month after it suspended withdrawals from trading accounts. Launched in October 2018, OKEx’s pool used to rank as one of the tenth largest in the world, according BTC.com.