It is legit, which does not mean that it can't turn into a scam later on,... It can be used by scammers, it can be used by phishers, it can close your account, it can freeze your funds, it can be hacked, it can go bancrupt,... but for now (afaik) it's legit...
Only use exchanges you trust, investigate before using them, and only keep your funds on an exchange for as long as you need to complete the trade... Always store your funds in a wallet for which you're the only one in complete controll of your private keys!