If there is a success story of someone who borrows thousands of USD from a bank, then gets a big profit from buying BTC when the market is bearish, then sells when the market is bullish... that can happen, but how likely is it that it will happen to us when we imitate it??? no one knows.... instead of discussing loans to be risked, it is better to focus on the main job that brings greater profits so that you can invest in crypto with even more amounts.
Taking loan from bank to invest on cryptocurrency is not a good risk to take at all, even though you know someone that has done it before and it worked for him or her is not advisable that you try it because cryptocurrency is very volatile and anything can happen at any time, a lot of people are in big debt right now because of taking loans and investing it on cryptocurrency and it failed them, I know of a lady in my home town who was into cryptocurrency investment she loved cryptocurrency so much and she was making huge amount of money from it, so one day she decided to expand and then went to take loan in a Bank and then used the loan money to invest in a certain cryptocurrency and she lost the money and she sold all her properties and brought out all her saves to pay off the debt after that payment she became broke till date and she has stopped crypto investment.
Instead of you to borrow money or take loan from bank or anywhere why not accumulate Bitcoin little by little, and before you think of going into crypto investment you need to have a source of income, that means you need to have something doing were you will be getting paid weekly or monthly, if you don't have a source of income then don't bother going into crypto investment because you will fail.
A lot of people really don't understand how crypto investment works one needs money to going into such investment without having money is impossible to succeed in crypto investment.
No one should borrow money or take loan just to invest in crypto.