This is just free $50 chips for you to gamble (in exchange for your KYC information).... you'll lose the gamble soon for most people. Unless you are great short-term trader.. most people wouldn't benefit from this too much. You can only withdraw up to $1000 if you win in the gamble using the money (per the term discloses)
Note that this is a CFD exchange. $50 accounting opening bonus is quite standard bonus among CFD exchanges. Another one (based in Australia) is offering similar bonus for Forex CFD exchange.
My recommendation for most people is to leave this promo out unless you know what you are doing.