Popular exchanges like binance or kucoin have to close registration of new users due to high demand on their services which they cannot handle. Once per day or two days binance reopens registration but does not inform users about it to receive instant notification when binance registration reopen add your email at http://checkbinance.herokuapp.com/.

Binance

Binance is now the most popular cryptocrrency exchange it has highest volume and allows to withdraw up to 2 BTC without verification. Right now binance registration is open so if you want join you can do it via this link > binance registration <