I guess that's the part I'm still cloudy on. The number is in relation to the day's volume, so it's a count of the shorts during the day. However, a day like yesterday with over 400k shorts open seems way to high. Same for the day before where over 500k were open. I would think that if the NSS don't get reported, then the short number is representing something else and may not be real useful.
EDIT: I'm not even sure how to word this question. The whole thing is pretty confusing.
Market Data 
Markets 
AI
