Wait for XMR to crash and buy the dip, then wait for the next pump and you'll double your money.
I don't think it's that simple. Monero is on the rise from Aug. 20, people are still buying it and it's very hard to predict when the crush will happen if it will happen at all. And if it will happen there's no guarantee that the price will be doubled in one year.
Neither me nor anyone else can tell you how to double $100,000 safely, in that I'm sure.