Vitalik Buterin has raised concerns about the potential threats posed by institutional investors like BlackRock accumulating significant amounts of Ether. Speaking at the Devconnect conference in Buenos Aires, Buterin highlighted two existential risks: the alienation of Ethereum's core community and the possibility of making detrimental technical decisions. He emphasized that institutional dominance could compromise Ethereum's decentralized ethos, leading to geographic centralization and the exclusion of privacy-focused users.