Sox: The SEC added the "grandfather clause" just before Reg SHO was published and did so without discussion. They did so because brokerage firms added if they didn't many would go bankrupt. Have you ever heard of grandfathering crime? That is exactly what they did..
https://search.yahoo.com/search?ei=utf-8&...991_012518
The SEC looks the other way when it serves their interest. They have been captured. Go IPIX!!!