[COMMENT: There are two thoughts that come to mind here. Firstly, the investment period quoted below of 90 years is not relevant to many retail investors, and it is easy to cherry pick a start and end date for comparative purposes to suit the hypothesis. But secondly, and of more interest, is the notion that a small portion of stocks produce the greatest returns. So how can we spot these?]
(19 June 2017, AFR, p22, by Chad Slater)
‘Does the average stock outperform cash? No. – This sentence almost seems nonsensical – of course we know the stock market does better than cash through time, so let’s start with a question: What is the average annual return for US equities over 90 years? OK, got that in your head? Now what do you think the average stock return is over 90 years?
‘This is what is called the positive skew that exists in equity markets: most of the gains that come from holding equities come from a very small subset of stocks. Positive skew is when the median (the middle outcome when everything is lined up in order) is below the average (the sum of total outcomes divided by the number). People’s wealth and incomes have this distribution for example, skewed by a few billionaires.
‘If we return to the title, a paper by Bessembinder shows that 58 per cent of stocks have lifetime holding period returns less than the one month T-Bills (cash) and less than half are even positive. The average lifespan of a US equity is just over seven years.
‘On the other side, the skew is incredible. From 1926 to 2016, of the 26,000 stocks listed in the US during that time, 86 stocks (or 0.3 per cent) generated more than 50 per cent of the total return. The next top 1000 (4 per cent) generated all the excess returns over cash, with the other 96 per cent matching cash.
‘So what does this mean for equity investing?’