I forgotten a site where I've invested only 1mbtc and got 8mbtc. If anyone knows about it please let me know. also similar sites like that will do. Thanks for reading.
Topic title is somehow misleading when we are reading on the OP queries. Some users already gave you the website on which you could able to multiply your bet on a particular winning. Im not really awared on these kind of sites but they are good though but winning chances are too slim.