Investing.com - With the stock market in a volatile funk, Wall Street analysts are beginning to blame the Federal Reserve's actions to tighten monetary policy, not worries about a trade war, inflation or a regulatory crackdown on Internet companies.Wall Street firm Stifel first raised concerns about the Fed, saying the central bank had become more "hawkish" in its view of 2019 and 2020. The firm said that the Fed would take an aggressive approach to interest rate hikes, triggering a bear market in the coming year. Bank of America (NYSE:BAC) now says that the Fed is the "simple reason" risk assets, including stocks, are struggling in 2018 because investors have been forced to acknowledge that a "tightening cycle is well underway."Not only is the Fed committed to raising interest rates but it has also been reducing its balance sheet by selling bonds and mortgage backed securities.Analysts may not be that off base. History shows that most recessions and bear markets, which tend to coincide, are triggered by Fed rate hikes.