Let's get the bad new out of the way quickly: For the year 2018, the S&P 500 fell 6.2 percent, the Dow Jones industrial average dropped 5.6 percent, and the Nasdaq Composite lost 3.9 percent. That marked the worst annual performances for all three indexes since 2008.
Much of the blame lay on a horrible December. In the last month of the year, the S&P 500 and Dow both logged their worst monthly declines since February 2009, and their worst performances for the month of December since 1931.
How unlikely was the late-year decline? This year marked the first time since 1978 that the Dow finished out the year in the red after rising in the first three quarters. It was the first time the S&P 500 had done so since 1948.