actually in my opinion the rise and fall of bitcoin doesn't need a reason. bitcoin is indeed like that it can rise quickly and fall abruptly. but in my opinion sometimes the bitcoin market can also be influenced by the news. if there is positive news about bitcoin then the price of bitcoin will tend to rise. conversely when bitcoin is attacked by negative news or FUD the price tends to go down. and news about the Chinese president who supports blockchain technology is making bitcoin prices go up. because most investors and bitcoin miners are from China.