DOW volatility - Joke of the Day 400 pt swing in 15min

Today's Joke of the Day is an intraday chart of the Dow Jones Industrial Average. After trading up nearly 300 points, the Dow had a 400-point reversal from 3:47 to 4:00 PM. Some are attributing the late-day decline to an announcement from GE CEO Jeff Immelt that he aims for flat 2009 earnings, but could that really cause such a move? Especially since GE's contribution to the reversal amounted to a mere 6 points of the Dow's decline. Prior to this month, one could only think of a few events that would send the market down this much this fast. However, after what we've all experienced over the last few weeks, today's action is just par for the course. - Beaspoke