Blackrock is getting it's tentacles into Bitcoin
They not only hold shares in the biggest publicly listed miners, but they own shares in the other shareholders of the miners.
Example:
It's not clear what Blackrock's endgame is here: but the spiderweb of ownership means that they control a lot of the biggest bitcoin miners.
Some people think Blackrock have done the classic venture capitalist thing; which is to invest a bit in ALL the bitcoin miners and other businesses out there in th hopes some make it big.
But some conspiracy theorists think they may be planning a 51% attack on the chain. Once they do that they can end bitcoin and issue their own coin.
I personally think that the global aspect of bitcoin still means it's decentralised. But at the same time it's sad to think of the demise of the small mining pools that did so much to make bitcoin what it is today.