The Benner Cycle: How Not To Predict Markets

When I first became interested in trading, I would often consult many traditional sources and old-school market wisdom.  I particularly liked the Stock Trader's Almanac. 

While there is real wisdom in some of those sources, most might as well be horoscopes or Nostradamus-level predictions.  Throw enough darts, and one of them might hit the bullseye. 

Still, it seems better than using astrology to trade. 

Want something easy to predict?  Traders love patterns ... from the simple head-and-shoulders to Fibonacci sequences and the Elliot Wave Theory.

Here's an example from Samuel Benner, an Ohio farmer, in 1875.  That year, he released a book titled "Benners Prophecies: Future Ups and Downs in Prices," and in it, he shared a now relatively famous chart called the Benner Cycle.  Some claim that it's been accurately predicting the ups and downs of the market for over 100 years.  Let's check it out. 

 

 

Here's what it does get right ... markets go up, and then they go down ... and that cycle continues.  Consequently, if you want to make money, you should buy low and sell high ... It's hard to call that a competitive advantage.

Mostly, you're looking at vague predictions with +/- 2-year error bars on a 10-year cycle. 

However, it was close to the dot-com bust and the 2008 crash, so even if you sold a little early, you'd have been reasonably happy with your decision to follow the cycle.

The truth is that we use cycle analysis in our live trading models.  However, it is a lot more rigorous and scientific than the Benner Cycle.  The trick is figuring out what to focus on—and what to ignore. 

Just as humans are good at seeing patterns where there are none ... they tend to see cycles that aren't anything but coincidences. 

This is a reminder that just because an AI chat service recommends something, it doesn't make it a good recommendation.  Those models do some things well.  Making scientific or mathematically rigorous market predictions probably isn't the area to trust ChatGPT or one of its rivals ... yet. 

We're seeing bots improve at running businesses and writing code, but off-the-shelf tools like ChatGPT are still known for generating hallucinations and overconfidence. 

Be careful out there.