Bull market may not last

Local analysis shows that rising stock prices near the end of their lives, based on previous shares trends.

The concept of “dog years” is something pet owners are familiar with, but what if that concept could be applied to the current bull market in U.S. stocks?

Michael Ball, lead portfolio manager with Northglenn-based Weatherstone Capital Management, has made that calculation, and it shows equity investors have a really old hound on their hands.

Measured against nearly two dozen bull markets dating back to 1900, the current bullmarket run, which started in March 2009, is equivalent to an 88.3-year-old person.

“We are very late into a normal bull market life span,” Ball said. “Problems will come up sooner rather than later.”

As of the most recent market high in May, the current bull market — at 2,262 days — ranks as the fourth-longest in modern history, stretching far beyond the historical average of 1,219 days, or 78.8 “human” years.

That isn’t to say the old geezer couldn’t keep kicking. The oldest bull market ever lasted from 1921 to 1929, or 2,932 days, the equivalent of 94.4 “human” years, before it expired into the tragic repercussions of Black Tuesday.

Several factors are weighing on the stock market, including slowing global economic growth, declining corporate earnings and rising bond yields, Ball said.

Stock valuations are also rich, having crossed into the top 10 percent as measured by Yale University economist Robert Shiller’s cyclically adjusted price-earnings ratio.

Once that happens, the average return for the S&P 500 over the next seven years