The Monster Platform provides a fixed rate of return over a one month lock in period. At the end of that month you can withdraw, top up or select another scheme. The rate of return depends on the investment amount.
4% per month requires 100 to 5000 MON
5% per month requires 5001 to 15000 MON
6% per month requires 15001 to 25000 MON
7% per month requires 25001 to 35000 MON
8% per month requires 35001 to 50000 MON
http://platform.bitcoinmonster.org/