It is advisable not to keep funds in an exchange for several reasons. Firstly, exchanges are susceptible to security breaches, and storing funds on an exchange exposes them to potential hacking attempts and theft. Secondly, exchanges may have limited control over their users' funds, as regulatory changes or operational issues could lead to frozen or inaccessible accounts. Additionally, keeping funds in an exchange means relinquishing direct control over private keys, increasing the risk of losing funds if the exchange experiences technical difficulties or becomes insolvent.
Therefore, it is recommended to store funds in secure personal wallets, where individuals have full control over their cryptocurrencies and can ensure their long-term safety.