It's all a mystery to me but I'm guessing it was a lot of profit taking. I'd love to be able to find out the block size of the trades. I picked DLTR up about 22 months ago and was thinking about selling but the news release of a rosy future made me decide to hold on. It'll come back and should pass through 60 within 3 months, I believe.
Please enough with the shorts will be squeezed nonsense, the short ratios is <5% there are virtually no shorts to be squeezed, short squeezes happen when the short interest is high, look at SHLD 38% short interest.