The number of Ethereum held in the top 150 self-hosted wallets has reached a record high of 56.25 million ETH, as reported by Santiment. In contrast, the top 150 exchange wallets now hold around 9.46 million ETH, close to their lowest level since June 2018. This data indicates a growing trend of Ethereum holders choosing self-hosted wallets for increased control and security over their assets, potentially reflecting a shift away from exchange custody.