Obviously, they are waiting for ETH 2.0 this July and hoping that it will create a lot of hype pushing the price to grow and making a lot of money for them. I don't know about the demand though, but it's simply manipulation and pump and dump and then exit to get more profits.
And just today alone, ETH price jumps 10%, I was surprise as we are still far from July. But for those who think that we are in the alt season, I would say that you should wait a little longer. Perhaps we will see what's going to happen after this July if alt market will bounce back and recover for good and will have its bull-run.