Well maybe because of gaining users of bitcoin. It is more popular than ever. The rise of investors and users are one of the reasons why. More demand, higher bitcoin value/price. Though many countries banned bitcoin already, the bitcoin's popularity in the world is literally no joke. Months passed bitcoin was surprisingly improves itself. People that are now using bitcoin thinks of it as a very convenient job at home or maybe a part-time job. Maybe bitcoin became popular because this is really convenient and useful.