I happened to notice a massive spike in one of the coins I follow and did a bit of research to find out why. Apparently it was as simple as a fat fingered trade by an eager investor, and the price jumped by 900% for around 2 hours. Not a huge amount of volume, so guessing the damage was reasonably limited, but somebody's wallet is considerably lighter today.
Just goes to show the importance of checking your zeroes, not so important if you add an extra one, but a killer blow with one less.