There're two kinds of earthquakes. The first one is shaking up and down, and the second one is side to side. The up and down earthquake usually causes more significant damage to one's property. And the same goes for the stock market; up-down shakes cause money loss. The big shake did happen in the market on Wednesday.
Major averages fell more than 1% on Wednesday after a morning rally faded. After having advanced as much as 1.9% by late morning, the $S&P 500 Index(.SPX.US)$ gave up all its gains in the afternoon along with the $Dow Jones Industrial Average(.DJI.US)$ and $Nasdaq Composite Index(.IXIC.US)$ , which fell the most on the day. All three indexes breached key technical levels during the session.
Good luck to all the mooers, and hope you won't get hurt.