The Dow Jones Industrial Average suffered its worst one-day loss in more than six years overnight, prompting heavy losses across Asia and Europe on Tuesday.
While some debate remained about the catalyst for the losses, which began last week, few doubted that a stock market correction was now well under way as the Dow's cumulative losses in the past week exceeded 8%.
A correction occurs when an asset, security or other pricing mechanism such as a stock index falls more than 10% from its most recent cyclical peak.
The correction took on added significance on Monday, however, after losses in the US were among the sharpest seen since the global financial crisis, with the Dow - at one point - shedding nearly 800 points in just 10 minutes.
Trading volume was the second-highest seen this decade, suggesting positions were being unwound across the board and at a frantic pace.
The Dow fell 4.6%, or 1,175.21 points to 24,345.75 - its largest points fall ever, and its largest percentage fall since August 2011 when the US lost its AAA credit rating. The S&P 500 lost 4.1% to 2,648.94, also its largest fall since August 2011. The Nasdaq Composite shed 3.78% to 6,967.53.
In Asia, the Nikkei 225 Average in Japan dumped 4.76% to 21,603.5, while Australia's S&P/ASX 200 slid 3.2% to 5,833,3. In late trade in Hong Kong, the Hang Seng index was down 4.35% at 30,815.
In the first moments of European trade, the EuroStoxx 50 index fell 3.21% to 3,367.5. London's FTSE 100 lost 3.1% to 7,108.5, while the CAC 40 in Paris and Frankfurt's Xetra Dax both opened 3.5% lower.