Goldman Sachs has raised its U.S. inflation forecast and lowered its growth outlook for the year, citing persistent energy-driven price pressures and increasing downside risks to economic activity. The bank warns that U.K. inflation could reach 4.9% by spring, which could hinder the Fed's efforts to bring inflation back to its 2% target. Energy prices are a major factor in this inflation surprise. However, investors are not fully pricing in the inflation shock, which may lead to a growth slowdown. Goldman's warning suggests that investors should prepare for both inflation and slowdowns.