Fastest way to achieve that kind of return : futures, Forex or options. With Forex for example, bet on any currency pair (long or short it does not matter), 200 pip stop, 200 pip target, full leverage (50:1) and you could quadruple your money in 3 days or less that way. Or lose it all.
That's the problem with most traders, especially new-comers: high and extremely unrealistic expectations. Some of them would have no problem believing that a 100% average monthly return is easy ! If they could just forget that nonsense and concentrate on making "just" 1% to 2% a month consistently, they would already be way ahead of the game.
Hit a sports betting agency and bet all your money on Brazil to win the World Cup. Anyone wishing to bet against that bet, send me a PM.