Achieving a big profit and doubling your account in a few months is fairly easy. The tricky part is doing it without risking to lose your money.
I have coded EAs which are designed to withstand a financial shake-up like one of those over the past decade. I am currently running them on live accounts, you can find them on my profile. I´m achieving a few percent per month currently. This could be upped, but it would increase the risk. The current setting is oriented on the big meltdown in 2008.
If you want your money to be safe, use an EA that withstands backtests of minimum 10 years on several brokers, as well as on broker independent tick data. Look for continuous profits without big drawdown.