Stock market movements over the past few months have been characterized by increased volatility, as uncertainty became paramount. And as new pieces of the economics puzzle are added every day, investors are increasingly grappling to make sense of the most likely direction of stock prices.

It seems to be a case of so many pundits, so many views. Has the market started bottoming out, or are bourses still in the grip of the bear? Or is a “muddle-through” trading range in store?

It's one thing to trade the market’s rallies and corrections, but this is easier said than done, with not many people actually getting it right with any degree of consistency. Others are of the opinion that the recipe for creating wealth is simply to follow the patient approach, saying that “it’s time in the market, not timing the market” that counts.

This gives rise to the all-important question: Does one’s entry level into the market, i.e. the valuation of the market at the time of investing, make a significant difference to subsequent investment returns?

In an attempt to cast light on this issue, my colleagues at Plexus Asset Management have updated a previous multi-year comparison of the price-earnings (PE) ratios of the S&P 500 Index (as a measure of stock valuations) and the forward real returns. The study covered the period from 1871 to October 2008 and used the S&P 500 (and its predecessors prior to 1957). In essence, PEs based on rolling average 10-year earnings were calculated and used together with 10-year forward real returns.

In the first analysis the PEs and the corresponding 10-year forward real returns were grouped in 5 quintiles (i.e. 20% intervals).



The cheapest quintile had an average PE of 8.5 with an average 10-year forward real return of 11,0% per annum, whereas the most expensive quintile had an average PE of 22.6 with an average ten-year forward real return of only 3.1% per annum.

This analysis clearly shows the strong long-term relationship between real returns and the level of valuation at which the investment was made.