If members choose to follow my trades, then depending upon how much they are trading, this creates the possibility of market impact. While the equity instruments we trade have plenty of liquidity, so that it is difficult to influence them, it is still possible and we would like to avoid that, for all of our sakes.We don't want members competing with each other for good prices. We are increasingly using options, which do have less liquidity than underlying equities, so keeping the number of traders down is especially important now.