As in Regulation SHO, the pathetic attempt to reign in naked short selling or the failure to deliverer of purchased stocks. The rule had no teeth because those that were short, didn't have to deliver the stock, because they were "grandfathered in." The grandfather provision is eliminated on Monday, but those participants will have until the end of the year to close out their naked shorts. (35 trading days). The list of stocks on the below link.
Here's why it is problematic. I'll use Take-Two as an example, because this stock has been hated by the bears forever. In August, TTWO had 31.7 million shares short, out of the 74 million shares outstanding. Institutions hold 95 million shares of TTWO, 20 million shares more than the total outstanding!
Overstock (OSTK 34.92) has been on the list for two years. As long as the price of the stock stayed down, the shorts could sell phantom shares, to offset any real buying to suppress the stock. This is the argument that the bulls made. The bears scoffed at it. But what has happened to OSTK's stock price as we approach the end of the grandfather clause? It was at 18 at the end of July and it's now at 34, and we know that the short interest only went down by 1 million shares in that time frame. Wacky Patty, as the bears call it's CEO, claims that the amount of shorts in OSTK is over 10 million shares. Maybe it is. Whatever you think of him, he's been winning the arguments in his lawsuit against the bears, and OSTK is the poster child stock for Regulation SHO.
Check out the list; there are stocks on here whose price has been affected by the bears shenanigans, and you have a wide assortment to chose from. One stock that has a particularly vocal contingent behind it is Local.com (LOCM 6.78). It may be worth a look.