The recent Bitcoin difficulty adjustment which took place at block number 578,592 resulted in difficulty levels reaching an all-time high. The difficulty of mining on the Bitcoin network increased to 7.46 trillion with the previous difficulty high recorded in October 2018 being 7.45 trillion. The previous high took place a month before hundreds of thousands of miners were estimated to have come offline. The recent difficulty increase has taken place after conditions for Bitcoin miners became increasingly lucrative.
Sources: BTC.com, Statoshi.info
