A platform I'm invested in, hextratrades.com, is requiring the purchase of HG (high grip) keys which cost $5000 in order to withdrawal. As it was explained to me, if the platform only trades binaries, keys aren't required for a secure withdrawal. However, being this platform trades and mines, keys are required. Seems a little hard to understand. Is this another money grab or is the a legit thing to have to purchase?