I have $100,000 to invest but want to safely double it in a year. Any suggestions?
If you bought all of it with bitcoin and ethreum you are likely to double your money easily,you can also invest on stocks or you can lend it to some of your trusted friend with 10% interest monthly,there are a lot of ways to make it grow,just don't do gambling .
Ya obviously never do gambling with that,but other ways you mentioned are also cannot easily double your money as you said.The safest would be do a fixed deposit in the bank and then wait for 8-9 years.Other than that all other methods will involve risk of loosing them as well.
He cannot gamble but he can make gambling as investment and it can be possibly add to his profit to make that capital doubled. But it seems that very low profit you can make with bankroll casino's but still that is going to be a good way to get some additional profit. And if op invested way back year or two ago, he can already doubled it.