From Bespoke Investment Group:
The Nasdaq is now down 18.37% from highs reached on 10/31/07. A bear market occurs when the price declines by 20% or more after previously rallying by 20% or more. While it's not yet a foregone conclusion that the Nasdaq will turn into a bear, it's getting very close, and investors should be prepared for what the typical bear looks like. Since the Nasdaq index was created back in 1971, it has suffered 13 bear markets. The average bear has been 216 days long for an average decline of 36.51%. Only 4 out of the 13 bears saw declines of less than 30%, and 4 bears saw losses of more than 40%.
BIG, always worth a visit. Here's "It's a Mess Out There"