Goldman Sachs released a research note Friday on the recent pullback in U.S. equities. The year-to-date drawdown of 5% is "consistent with historical experience," they note. However, Goldman warns the current drawdown's lower magnitude vs. the historical median suggests at some point the S&P 500 might decline further (to the mid-1,500s) over the next six months. The firm reiterated its view that the index will close 2013 at 1,750, 10.7% higher than its level early Friday afternoon.