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 thing to do is to keep calm. Good timing comes to those people who is patiently waiting for there turns to come. Don't panic since bitcoin is very unstable right now but somehow we should keep in our mind positive side. Waiting is a virtue and I know if investors are rare in this times who knows sooner or later investors will invest a huge amount of money in bitcoin and bitcoin will be boom again.