Thursday, May 18, 2006

What the Relative Range is Telling Us About This Decline

Recall that the relative range is a measure that compares the range of the last day or week with the median range for the past 20 days or weeks. The logic behind this is that people's psychological responses are to relative events, not absolute ones. They will, for instance, react differently to a 40 degree afternoon in summer than to a 40 degree day in mid January.

Yesterday, we had dropped 4.3% on SPY for the past five trading sessions. The five-day relative range was 2.39, which means that the range was more than twice the median five-day range for the past twenty days.

Since March, 1996 (N = 2551), when SPY has been down 4% or more for a five-day period (N = 120), the next five days in SPY have averaged a gain of 1.03% (75 up, 45 down). When we look at occasions when SPY was down more than 4% *and* the relative range was twice or more its median (N = 36), the next five days in SPY averaged a gain of 2.31% (25 up, 11 down). Conversely, when SPY was down more than 4% and the relative range was less than twice its median (N = 84), the next five days in SPY averaged a gain of only .48% (50 up, 34 down).

What this suggests is that periods such as the current one, in which a steep drop is accompanied by a sizable expansion in the relative range, yields superior returns in the near term. Perhaps this is because the large drop on a large range represents panic selling of short-term traders, creating value for longer timeframe market participants.