Signal vs. Noise
By combining the diverse price actions of many stocks in these indexes and reporting on their small combined price moves day by day, it appears that only modest changes may be going on. Maybe it’s just another year when market prices rise their usual +9%, or maybe a bad year when they decline -5%.
But let’s look at what is happening to specific stocks’ prices. After all, they are what you may be investing in and risking your capital through.
I systematically follow about 2,500 stocks, ETFs, ADRs, and indexes on a daily basis. In 2007, there were only 74 that had price ranges during the year, low to high, of less than 20%. There were also 221 that had price ranges of 100% or more.
These are all stocks the academics and economists tell you that go up some 9-10% a year on average. You’re aware, of course, of the statistician that drowned while wading across a pond that was only 2 feet deep, on average?
That 9-10% is what physicists call signal. The 100%+ is what they call noise.
Both offer opportunity. But where is the greatest, most frequent opportunity?
The average price swing during the year was about 68%, several times that 9-10% trend. And 2007 was not an unusual year in the market. Not like 2008.
As important, how long did it take a typical stock to make its traverse? About 7 months. So the value of perfect information (i.e. hindsight) was an annual rate of change equal to 222%. That’s the gain you might have had with a perfectly timed buy and perfectly timed sell, on stocks representative of the average, that could employ your capital fully over the year.
Not likely, so what are the odds that good timing could do better than the 9-10% trend? We can get a sense of the answer by finding out how many stocks out of the total produce a price upswing gain greater than that. The answer, in 2007, was 65% of them – even when we recognize that many of the stocks’ price swings were downward.
Big potentials exist in the noise. And they are magnified by the time component. More about that another time. Till then, make some money for yourself in the market.
Peter Way, CFA