First things first, I’d like to ask: can you pay off the loan if your investment doesn’t go as expected?
Assuming the answer is yes, then go ahead and take the loan..
Even if answer is yes, he shouldn't take a loan from bank to invest in bitcoin. Ideally, we should invest in bitcoin what we can afford to loose, and if you have to go into debt in order to invest that means that you can't afford it. Simply, its a bad idea.
thing is, even if Bitcoin doesn’t pump within the timeframe you’re expecting, it will likely increase over time since all these positive news factors can drive its price higher. however, keep in mind that there are no guarantees, so you’ll need to accept the risk and trust your instincts.
He doesn't plan to just buy and hold, he plans to actively margin trade, meaning he could loose everything.