The cryptocurrency analyst PlanB recently released a mining difficulty chart on Twitter. The data shows that the price of bitcoin may reach $31,000 by 2021. PlanB combines bitcoin price statistics with mining difficulty to analyze that BTC will experience a regular mining difficulty cycle corresponding to the valuation change. Over time, Bitcoin's price increase has declined after experiencing a low point in the difficulty cycle, rising by 50,000% at the end of 2013, and increasing by 9000% in December 2017. Considering that the current cycle (occurring in December 2018) is relatively difficult to mine, PlanB predicts that by 2021, the price of BTC will once again peak ($31,000). However, the expected valuation range of Bitcoin seems to have changed even more. According to its forecast, the price of BTC may be between 30,000 and 300,000 US dollars.