RE:RE:Interesting close at $1.20@zenj - I asked IIROC how many downticks somebody is permitted to make before UMIR is violated and I received a form letter, the same as the one dman34 posted, without an answer to my question. My guess is that it's an arbitrary number and there is no "line in the sand" as it's extremely difficult to prosecute. A HFT could simply defend themselves by pointing to "300" other trades they've made in a day and compare it somebody who had one trade during a day which was the last of the day and claim that the person who made the one trade at the end of the day is the person who is manipulating. IMO market regulations are rigged to favour "institutions" - but they seem able to explain everything away.