To double it safely i will build a food business which most people really like. I'll build a restaurant spending all $100k. Although doubling it will require some time but it will be safe in that way. Rather than investing it on some networking or use it as trading capital which have a high risk of doubling money.
I think business is still at risk. many restaurants in my town went bankrupt because they could not compete with competitors, yeah it is the risk of a business,
there is always a risk, if you do not want to see the risk. Do not grow your money
Yes, Even if you just build your own business and don't do investing or trading, it doesn't guarantee that you will double your money risk free . OPs wish to double his money safely is just a mere dream as there is no safe way to do it .
If you're planning to build a business you must think of something unique that most of your competitors have cause customers always go to the better one .