You've got to find a coin that gives you a combination of relatively low circulating supply, high volume, and pending release or big news. 

VechianThor for instance doesn't have the lowest circulating supply but it's in the top 20 for daily volume and it has the Xnode activation on 3/20/18.  Now, does this guarantee you doubling your money?   Nope.  Especially in 2 weeks.  But it is an example of an altcoin that might have a price spike for quick profit.

If you end up going to the casino, play roulette and bet red. 

Good luck.