Quote from dtrader98:
In all fairness, they should bust both sides of the trade. I.e. anyone who bought long and had the trade busted should have the corresponding sell busted as well. Assuming OP scenario is true, there is a very valid complaint here.
Maybe I'm missing something, but I don't see why it would be so difficult to match up any round trip positions during the bust action (FIFO) and invalidate them.
That would be a logistical nightmare, since every trade has a counterparty.
The clearly erroneous guidlines are posted in every exchanges bylaws, but in practice are not formulaic. They are judgment calls. The 60% up/down that the exchanges collectively agreed to was by far the widest spread I have seen deemed to be standing trades. Though, I can not remember another time when the entire market went clearly erroneous. Usually it is just one stock.
But as I said - there must be rules before the fact, not after. Because next time Dell gets scared that a competitor is going to offer ultra cheap laptops in the next few months, and Dell wants to offer their merchandise for 60% off - nobody will dare buy anything causing huge inventory problems for Dell.