someone sold stock and there weren't enough buyers to soak it up at a higher price
I mean, if OP thinks about it, how often has he fat fingered a trade, had to liquidate a position to pay taxes or bills around the house or cover margin for another trade.It's a flippant answer but it's true. More sellers than buyers and without a credible hard news source you won't find out for some time if at all.
This was the last 3 days of EXPR. 5/18TH MINUS 3 DAYS.When was this? If you give me time frame I can look it up for you.