It's a snapshot of all open shorts on that day. If the shorter closed prior to that day by an offsetting cover, then that short interest (now covered) does not appear on that day. Hence, it is a snap shot.
Your quote:
It is a record of all legal shorts from any date in the past 12 months that is still open
Still open on that day... a snap shot, NOT a cumulative accounting of all the short that occurred but closed prior to that day.
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.