The biggest crypto fund Grayscale Bitcoin Trust bought another 15 114 BTC last week and fund's crypto AUM is almost $10B with 506 000 BTC. In my opinion such BTC stockpiling can be dangerous like a 51% attack but I didn't find any information is Satoshi Nakomoto ever mentioned that.
The possible chances for the 51% attack is very low. As of now the holdings
Grayscale own contributes 2.29% of entire marketcap of bitcoin. With this it looks like Grayscale staking the bitcoins at regular time interval. Satoshi wanted things to be used without large scale accumulation. 2.29% doesn't look like a big accumulation.