from the wsj Rosenblatt Securities Inc. estimates that high-frequency traders would have made, on average, five cents to 7.5 cents per 100 shares traded in the U.S. stock market in 2010. That is down from 10 cents to 15 cents per 100 shares in 2008. "Times are lean," said Manoj Narang, chief executive officer at high-frequency traders Tradeworx. Those #'s seem quite high. And lean?