I have always wondered who are the firms on the street that has enought power and respect to use market rules in their favour. Like rules governing obviously bad trades or trades made in error. If you don't include the obvious like the big 4 prime brokers, who are the firms. The reason for my question is that I read about a japanese bank that made an obvious mistake in selling their jcom shares. It was a misquote. The bank was pretty big, but they weren't able to pull market rules in their favour. But then you have the case of coco, where the firm was able to pull market rules in their favour. But in that case, it wasn't a slam dunk case of obvious mistake.