After researching the news sources, I decided to pledge my land and houses worth $ 40000. I use it to buy 4 Bitcoin
I will rent a small apartment with my family
I'm happy now
I believe that the BTC will increase to $ 20k next year.
I am truly amazed by your courage to buy 4 Bitcoin and hope that the price of BTC will rise high in next year. we will not know what will happen in the future and cannot predict the price of Bitcoin, in my opinion it is very high risk and hopefully you are lucky can to get a big profit in next year if Bitcoin prices can to reach $ 20K. if I have a lot of money like you I would also do the same thing.
The decision he made was actually a right one, but I feel he went about achieving it in a wrong way, the worst thing he can ever do is to take loan for such a high volatile market, and we all know that loan has a time frame, we could say that bitcoin will rise to that $20k next year and would not rise, may be the upper year which might have made him loose his house already, and for an investment that you are getting times 2x, I am not sure that it was worth all the risk that much.
The best would have been for him to put little saving into it and allow it to grow even if it does not have to be much, and I feel greed is still what made him sell everything to want to get 2x first. If I were him, as I put the $40k, if it increases to like $50k, what I would do is to remove the $40k to pay and then continue with the remaining $10k to invest with more.