Yes I have witnessed it but most of people are not aware what bitcoin is capable of doing because when i learnt completely about bitcoin i was hesitant to invest $200 when my friend's did invest in that and in about 3 to 4 years they have already gained an return of almost 600% more than what they have invested so i have seen many fluctuations like this $100 - $300 but the bottom line is bitcoin gains the value back and much more than the price dump. Now it was dropped from $1150+ to 3 digit and now i am sure once it gains the value it will cross the value of $1200.