They are scammer. A nick name

They are scammer. A nick name called Amanda and Jason invited me to trade second contracts on sigbc.com & sigtf.com. After a few trades i can withdraw the money from the site. But when i deposited over $50,000 and try to withdraw it, they ask me to deposit more 15% of my account to verify the taxes. When i ask them back all they trying to do is rushing me to follow the instructions. When i realized i got scammed it was too late.Maybe there're a few people 're got scammed like me. Hope this report can prevent them asap.