It is hard for newbies. But many pro traders do that easily.
Yes, it's possible to turn $200 into $400 in six weeks. The trick is hitting really big trades with a great risk/reward situation. The key to executing this strategy is that you always have a tight stop that is in place. If you're wrong, you know very quickly, and get hit with a loss. Let's use a 5% loss for example. If you're right, and your risk reward is 1:5 - you make 25%. Of course, using that kind of leverage is dangerous. Trying to do this repeatedly in the long term will most likely result in a blown up account.
There are risk-lovers and there are risk-haters, but the best traders will take the risk as long as they get paid for it.