They probably would not "see an investigation". However, if the SEC has become curious, they can seek reassurances from the brokerages that they have the inventory of shares required, and confirm that they are following the rules and regulations There is incredible regulatory scrutiny right now on broker-dealers. Half of them don't even know where their next violation might come from because they are so sloppy knowing ALL of the details on how they follow the rules. In the past, they just had to know enough to say their spiel, that allowed them to believe, and the regulator to believe, that they knew what they were talking about and they were following the rules. Now, everyone is drilling deep and lots of holes are being found at many levels. The broker-dealers and banks hate it. That's why they are happy Trump will soon call off the dogs. Back to how they've always operated, loose and free - with no scrutiny.