There is always a flip side to every coin. My personal guess is they are selling shares that they will buy back later at a premium from the purchaser as a short term loan to fund new large orders till they get the accounts revolving. I think the earlier buybacks support this theory, but it is a theory.
They do not want the less than honest brokers to know the amount so that they do not flood the market with NS shares not cleared through the DTCC.
Market Data 
Markets 
AI
