Well, there is not only a chance that Bitcoin will be down; it is always expected that Bitcoin's price will go down every now and then. The market of cryptocurrency, which is led by Bitcoin, is a volatile one. There will huge ups and downs all the time. So there is no way there will be a late investor. Just enter anytime or at the dips to have a cheaper buying price. I cannot imagine any altcoin replacing Bitcoin. So far, there is no sign that it will happen. Neither is there any valid reason at all for its replacement. Let's just stick to the reality.