now a lot of investors are investing in bitcoin, therefore bitcoin has increased very rapidly, if bitcoin decreased what should be done?, whether the investors will lose? 
I think the best to do if the bitcoin is decreases is just hold if have invest in bitcoin. We need hold your invest in bitcoin to think if the value of bitcoin is increase again to make sure you earn lot in your investment in bitcoin. It is not lose of a investor in bitcoin just be calm don't be panic give patience in bitcoin.