he went and sold his property to invest on Bitcoin without been knowledgeable about it. he went ahead and invest but loss everything because he doesn't know how to trade Bitcoin.
Do not get it wrong, your friend did not invested in bitcoin, he was trading which is another thing entirely. Bitcoin ATH is $69000. Bitcoin today price is $29800 now. Even if he invested in bitcoin at ATH, he would not have lost everything. And bitcoin will still get to $69000 and increase above the price, only what is needed is time.
If he invested in bitcoin, time of profit will come even if he invested at the wrong time.
The challenges most newly adopters of bitcoin are facing is as a result of lack of research on bitcoin use cases, for they can't clearly differentiate between investing and trading on bitcoin. Investing In a hurry without a plan target wether for a short term or long.
The price position at which you entered your investment also determines yours duration plan for your investment to start yielding profit. Nobody really loses on bitcoin so long as they have patience with their investment, and this patience is borne by your knowledge of what you're doing.