Probably the fact that I sold 6 bitcoins at around 150 dollars. I mean at the time that was actually quite good amount of money for me and I really didn't need to sell it but I got it so much cheaper so it looked like a great deal, at that time I literally spent that money to go to a vacation so at the time it looked like I spent like a hundred bucks on something that turned into a huge vacation, that was really something I was quite happy about. Of course not so happy about it anymore because that could have been around 70 thousand dollars by now if I kept it, I couldn't have known it would have increased so much, at the peak of it 6 bitcoins was worth 120 thousand dollars, that is insane to think about it now, I regret not holding for longer. However it helped me to realize maybe I should hold longer, so thats what I am doing right now.
You mean 6 btc for a total of $150 or each. My biggest regret is also just like yours but I joined a little bit late and also sold my coins at cheap price of $1.1k and if i would have kept them with me right now then their cumulative worth would have been more than $60k, so i chose to sell my coins a little too early in desperate times or maybe I was thinking that I had made enough profit from those bitcoins.