Due to heavy traffic on every crypto market, they are closing registrations. Its good idea to open accounts just in case. On some markets people buy accounts for $$$.
Here are links to most popular and best markets with short description.
Binance: https://www.binance.com/?ref=18930106
New market with many ALTcoins, no FIAT. Registrations limitetd per day. No verification needed.
Gate.io: https://gate.io/signup/709501
Probably the only one market with open deposits of SBTC. No verification needed to trade crypto.
Bittrrex: https://bittrex.com/
Market without FIAT. Many ALTcoins. Basic verificatiion needed. (registration temporary closed)
Kucoin: https://www.kucoin.com/#/?r=25tP4
Many ALTcoins. No verification. Nice promotion: https://www.kucoin.com/#/ranks/RPX
WELCOME AND THANK YOU MY FRIEND