It's because of the news about the merge, the PoW and any other news related to the upgrade of ETH network. There will always be a significant gain that we're going to see.
In my own opinion, most people are starting to go back to Ethereum or some are moving there for some reason for sure, they trust Ethereum more and also about the upcoming updates on Ethereum for sure.
It's because of the updates and news and eventually, when it's done, they're going to be spread again in different altcoins or most of them are going to be back for bitcoin.
This is what happens when such news are around the corner and everyone of us smells that the upgrade is going to be worth it. So, those that has ETH are seeing to be fine locking it on LPs or for the 2.0.