There are a lot of sites that are promising really nice earnings just investing few btc..300% in one or two days? Dont trust them, probably they will stole your coins. Dont trust ALL sites you navigate in. The best way to invest your money and get a good return are the gambling and casino sites.
Other kind of sites (financials, mining etc..) are going to steal your money, or they will invest your coins in a risky way. Also remember that mining is not profitable anymore because you need to buy thousands of dollars in mining hardware and everyday the blocks difficulty is raising.
So, if you want to invest in a secure way your money try gambling sites. Usually they offers 10% to 50% return. In the section below i listed some tested bitcoin gambling sites.
moneypot – here you can invest or start your own bitcoin casino!