There's no one who can tell what's the reason but by reading some information on news and article, you might get an idea.

As a common reason, the bull run is a product of continuous demand. Looking at the chart, there are still largely sold out but the impact of large buy maintains the position. I like to see the price not to experience a massive bull run quickly as we don't want to see another hype. Currently, the growth is good, and no signs that the price increase is purely on hype.

Well-performing assets or investment or whatever you want to call it, even in the times of pandemic.