Just a few weeks ago, the Dow Jones Industrial Average hit a fresh all-time high. On Wednesday, after several days of triple-digit declines, it closed down more than 600 points having erased all of its gains for the year.
It's not always possible to pinpoint why the market is up or down at any given time, but there are several factors that likely have contributed to the recent sell-off.
Sure, by several measures the U.S. economy is strong. Unemployment is at decades-old lows and businesses and consumers have shown confidence. Economic output is growing.