.......but maybe he's just securing his money in a big exchange for fear of a problem with his wallet address.....
How can an exchange be more secure than a personal wallet?
A person who owns at least 4,500 BTC doesn't use Binance for storing his bitcoins.
4500 BTC i would rather keep safe on hardware cold wallet its too risky storing lot of coin on exchange

and i think he/she just want to buying altcoin or the program with DeFi that hot right now. because yes if i were him i will keep hold till the end 2021 that will be new ATH like people said about it