The Dow swung wildly on Thursday, losing as much as 998.50 and boomeranging back hundreds of points to close down 347.80, or 3.2 percent, at 10,520.32.
Theories abounded, including anxieties over Greece and the Eurozone. But the biggest intraday drop on record may have been triggered by an erroneous trade.
Video: Watch in "real time" as the market slides — and Jim Cramer spots a mistake.
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