We may or may not have hit the bottom of the bear market. If we have, it is worth asking, "How bad was it?"
There are a variety of ways of computing the decline in the stock market. There are different indexes and there are different ways of measuring the same index. Using data I could readily find on the Internet, the monster bear market was the 1929 to 1933 bear market, which saw stocks decline about 89%, Stock prices did not get back to 1929 values until the mid 1950s.
In the past hundred years there have been three other serious bear markets. In 1919-21 stocks declined 46.58%. In 1937-38 they declinded 49.10%. And in 1973-75 they declined 46.98%. (There were also two bear markets between 1900 and 1908 that were in the 45-50% range.)
Using a different series (from yahoo.com), I compute the 2007-08 decline as 46.66%. This is from the Dow Jones Index, with a peak of 14164.53 (Oct 9, 2007) and a low of 7552.29 (November 20, 2008).
So a few of the old men on Wall Street have seen a bear market equally bad as this one, but none of them have really seen anything worse. We live in interesting times.
(I consider the S&P index a much better measure of stock prices than the Dow Jones Industrials. The S&P 500 fell from 1565.15 on Oct 9, 2007 to 752.44 on Nov 20, 2008, a drop of 812.71 points, which is a 51.92% decline. [Ouch! No wonder my pension fund looks so bad.] That decline is more than 10% larger than the drop in the S&P from Jan 11, 1972 (120.24) to Dec 6, 1974 (65.01), a 45.59% drop. So based on that measure, and assuming there are no nonagenarians actively trading there, no one on Wall Street has ever seen a bear market as severe as the current one.)
See an update here.