July 16, 2008
Up by 3.12 percent, the NASDAQ gain is unusually large for a single day.
There have been only 86 such closes in the 2,145 trading days since January 2000. And just 16 of these were in the range of 3.0 to 3.25 percent.
Equally atypical are the 2.51 percent increase of the S&P500 and the 2.52 percent move of the DJIA.
In fact, this is the sole close, since 1950, when all three indices increased by these amounts on the same day.
Placing these gains in historical perspective, it is seen they have occurred mostly when the averages are falling, or are at the bottom and on the way up. This tendency, for the S&P500 as an example, is seen on the graph below. The vertical lines extending from the time axis indicate when the daily increase of this average was in the 2.50 to 2.75 percent range.
Looking at the next day, in the past and since January 2000, when these indices increased by the amounts discussed above, the NASDAQ moved up ten times and fell six times.
The S&P500 on the day after gains between 2.5 and 2.75 percent, fell four times and increased three times. The DJIA, also in this 2.5 to 2.75 percent range, had six negative closes and only four increases.
DJIA 2.52 percent
NASDAQ 3.12 percent
S&P500 2.51 percent