Why do you think BNB is a promising coin? You did not provide any facts or explanation. As well it is hard to believe that its price can double.
Lets me explain why I have such feeling. First, because BNB was meant to be a solution for expensive Ethereum transaction. BSC is almost a copy-paste of Ethereum blockchain. It helped in the beginning, but this can not push the price up forever. In fact BSC transaction fees also start to rise. Second - as Binance nearly force people to pass KYC, users outflow is inevitable. Third - holding BNB no longer give huge bonuses as previously. Previously users get decent rewards from launchpools, trading competitions and etc. Now you freeze thousands dollars worth BNB to get several dollars of reward.
I guess it is promising because it has Binance and BSC behind it and that is good enough reason to believe a coin can do amazingly. If you have world's biggest exchange and world's second biggest ecosystem behind a coin then that coin going up and continue to go up is not something unexpected.
I understand that there is a chance we could end up with nothing as well, every coin has that chance and BNB may go down under 50 bucks like it used to be, however do you really believe there is a good chance that may happen? I feel like there is a very tiny chance for that to happen.
This is why I believe there needs to be a clear indication of what BNB could be used for. BNB is used for both trading on binance, which is the biggest exchange in the world so it means BNB is used a ton for trading fees, millions of dollars every single day, and it is used for BSC transaction fee as well, which is again millions of dollars every day. There is good enough reason to buy and spend it, which makes it go up.