The ZeroHedge headline nails it:
Worst Start To A Year Ever, Stocks Down 5 Days In A Row
And the New York Times elaborates:
Stocks continued to retreat from their recent record highs on Tuesday, weighed down by an ongoing plunge in the price of oil. Bonds rallied as investors bought the safest assets, pushing the yield on the benchmark 10-year Treasury note back below 2 percent for the first time in three months.
The moves suggest that investors have little confidence the economy in the United States will continue to grow at the 5 percent annual pace reached in the final quarter of last year. As a consequence, company earnings will suffer. The reason behind the gloomy prognosis is a slowdown in growth elsewhere in world, particularly Europe.
The precipitous fall in the price of oil is good news for individuals but may auger bad news when viewed in the aggregate. Oil is a commodity, after all, and in an economic slowdown, commodity prices fall.
In a severe contraction, they fall and fall.