On Monday, August 24, the Shanghai Composite Index dropped 8.5 percent, its second such steep fall since late July, and its worst since 2007. On Tuesday, stocks fell an additional 7.6 percent. The steep slide translates into more than $4 trillion in losses on China’s leading bourse since its June peak. Analysts watching a resulting global sell-off are debating whether it is a long-overdue correction in an overheated market or a sign that a longer-lasting economic slowdown is on the horizon. —The Editors