PS: Although CoinArch seems to be a legit Bitcoin trading platform, so not a ponzi/double your investments scheme as you (and I) would think it is with the very brief description of the OP, I suggest caution nevertheless.
Especially when a service claims "We've used our 25 years' experience in financial markets to bring you industry leading bitcoin products which are easy to understand. " and if you check out the team...not a single member looks older than 25 tears old!