Investing.com - At least one Wall Street firm thinks the party's finally over for stocks. Stifel says its model of the S&P 500 shows "minimal price upside in 2018 and a bear market in the coming year." The firm says any decline will be "unusually rapid" and result from Federal Reserve policy errors. Stifel sees the Fed taking a more aggressive approach in raising interest rates, and is concerned about the central bank's "more hawkish view" for 2019-2020. The firm recommends investors take a defensive approach by buying utilities and consumer stapes. Stifel's price target for the S&P 500 remains at 2,800, which is below the benchmark's record high of almost 2,873 set n January. The bull market turned nine-years old earlier this month.