Pretty much anything could. A few months back, there was a lot of talk of people moving their retirement savings and even their home equity into Bitcoin. When you see that happening, you probably want to take some profits. Pumps happen because for whatever reason people believe they'll be able to sell later at a higher price than whatever they are buying it for now, and then lots of people get in on the buying frenzy. I actually don't like all that volatility. There are better ways to make good money in the cryptocurrency industry than buying at one price and selling at another. But at this rate it will take a hundred years for most people to figure that out.