Thursday afternoon, the Dow suddenly plunged nearly 1000 points. It quickly recovered, however, now down 340 as of 3:10pm.

The euro is also hit a new 14-month low against the dollar. Commodities are also declining.

News reports indicate that the market became spooked that Greece's problems would cause widespread instability in Europe. Investors fear that these problems could overshadow the global recovery. Greek lawmakers approved their austerity plan today.

While the current loss to the Dow is significant at 340 points, or 3.1%, it is far less alarming than the initial 1000-point fall. The other broad indexes were also off, the Nasdaq by 2.7% and the S&P 500 by 3%. We'll update this post if the market's recovery from its earlier lows reverses course.

Update 1: Now down nearly 500 points again at 3:21pm.

Update 2: Looks like Megan's first inclination is right. There must have been something wrong with the trading system. Accenture temporarily dropped to 1 cent. There may have been others as well, as it's hard to say without knowing what happened to the entire universe of stocks.

Update 3: None of the Dow components appear to have suffered an Accenture-like fall to a penny, the drop of that stock and potentially other non-Dow components (it remains unclear) may have triggered a quick sell off until the problem got corrected.