DTCC knows exactly when they took custody of the shares and whom they took them from. You know very well, FINRA has bluesheeted every trade. You know very well the SEC now has DTCC and FINRA's reports and are cross referencing every single trade.
Don't forget, in the blue sheets includes all account information, including name, address, SS/TID, phone, etc.
Then you know the FRB has EVERYONES information, so they will just pop in the SS/TIDs to the FRB and will know everywhere they have accounts.
So yes, every man, woman and whatever that purchased or sold this stock is now in the SEC database for this investigation to see who is whom.