Not possible in the least unless you want to be scammed out of your bitcoin. 
It's possible if his going to do gambling activities and if he have luck and skills to do that then he can possibility double his bitcoin that fast and if not of course his going to regret because he wasted his money to gambling where there's no guarantee of winning and if he are going to invest then goodluck too.There is no skill factor in gambling but it is all dependent on luck, no one can use any kind of skills in gambling to earn profits but if he is lucky he will get profits and if he is not lucky at that time then he will regret it for sure, so gambling is not a way of doubling bitcoins or money.