An Ugly Gap Failure?

The market gapped up big today but couldn’t hold on to those gains as the S&P 500, Dow 30, and Nasdaq all finished in the red. Reading financial columns tonight you’ll be told that the inability of the market to hold on to its gains was a bad thing. The large black candlesticks are ugly. Market participants are selling into strength. All of which means there is likely more downside to come. But is any of it true?

I ran a study on the Nasdaq 100 tonight to find instances where the index gapped higher by 1% or more and then closed lower on the day. I wanted to see whether the negativity tended to carry through to the next day or next several days. Here’s what I found.

Going back to 1986, the NDX has had 52 occurrences where the market gapped up over 1% and then finished negative on the day. It closed higher the next day 54% of the time. The chance of the NDX being up on any day over the period was also 54%. Over the next 3 and 5 days the chances of the market being higher were 62% and 65% after a large failed gap up. The NDX has closed higher between 55.5% and 56.5% of the time over all 3 and 5 days periods since 1986. So looking out over three and five days the supposedly negative reversal actually seems to be a positive for the market.

Even more compelling is the average gains realized over the period. For the 1-day following the occurrence, the market gained on average 0.4%. An average day in the NDX since 1986 saw a gain of 0.06% – much lower. An average week for the NDX was about a 0.3% gain. The average week after the failed gap up? A 1.3% gain.

If you thought today looked bad and you were worried about the market going forward because of it – you shouldn’t be.