At any rate, it was also explained that the short interest in GME could legitimately exceed 100% if there were large numbers of shares changing hands at multiple times during the course of a trading day -- i.e., Short Seller A borrows 100 shares from Short Seller B, then immediately lends the same 100 shares to Short Seller C, etc.
I may be totally wrong about this, but this is what I understand from reading up on this story yesterday here on FR and in other places.
People would overdraft their accounts, and there was an allowance of time for the check to be delivered, deposited in the recipient's bank, and then send the check back to the holder's bank to be cleared.
So, in the days of millisecond trading, there is a float period while shares are in the middle of trading?
-PJ