The daily transaction volume of bitcoin is always above $ 10 billion, this is what can make the value of bitcoin rise and fall significantly, but this is a good opportunity for investment because of the bright prospects 
I think Bitcoin is still want of many investors, that's why its price is continuously rising because the demand is growing. Also its good to invest to it because of good project and really most reliable coin too. Even there are so many coins existed right now Bitcoin is still dominance and it is most profitable to all. Even its price is sudden change it is still worth it, and can give you opportunity to get huge profit.