Goldman Sachs has appointed Paul Russo, managing director for equity derivatives, as head of One Delta, a unit that covers portfolio trading, exchange-traded funds, and stock trading, according to a firm insider. The appointment was announced by Mike Ryan, co-head of equity product group U.S. sales at a recent town hall meeting. Ed Canaday, spokesman for Goldman Sachs, said Russo will be heading the U.S. stock and U.S. program trading and will be based in New York. Russo heads the European stock trading desk in London and is now in the process of moving to New York. Calls to Russo’s office were not returned.