Quote from: Gwerrahar on January 10, 2017, 03:09:04 PM

Doubling coins is possible but not something that is done a lot because its something that is very hard in this bitcoin period.

Quote from: Ducksun on January 10, 2017, 05:02:04 PM

I think its right now almost not really possible with this price anymore maybe with some trading its possible but it will be very hard.

Both of you should read whats OP asked first before you give your opinion on here. OP asked about ponzi/HYIPs sites, he thought why there are some sites which offering double or triple your money? Actually all of those site will scam your money. It is not about bitcoin price nor how to double your btc (trading).