What is your perception of how people running trading businesses make money? There are many models in the spectrum of tading businesses. you mention IB's, brokerages and funds. these sectors seem to be focused on service fees, commissions and profit sharing. Every year it is proven that the largest organizations make the most money and rarely is there any incite on how people running trading organizations do better on making money in a normaized way, meaning dollar for dollar comparisons. When I survey and annotate these listed perfomances what I notice most is that there is little connection to their performance and what is going on in the markets in terms of what the market offers. What they make in a year can be seen in a few days of that year in terms of market change. What owners make is only a fraction of the earnings made and much much less than the market offers. These companies do seem to be expert is changing their size (A marketing endeavor it looks like or more recently, marking to market to do write offs). As an example, SAC, in greenwich does do securities trading and the CEO feels that he is in a dominos situation since what he could do would be done by others using his strategy.