My worst decision on bitcoin when i bought bitcoin on high price then a couple of hours the price went down and as a result i panic and sell it even i will lose a lot of investment. That's a newbie mistake from the past and it happens long time ago but now i learn a lot from that.
I think nobody knows when bitcoin prices will go down. So it's a natural thing when you buy and then the price goes down. As is the case today. Many people are losing because the price drops very quickly
That is the cons in using bitcoin, you will experience a huge price volatility but if you will just be patient and have a self-discipline then it will be the most helpful thing that you will ever had in facing the price volatility. Most of the people sells when the price drops but some of them have patience and self-discipline and they just choose to hold their bitcoins for long term and some more by buying cheap bitcoins from the dumps.