In his book, A Random Walk Down Wall Street, the author Burton Malkiel carried out an experiment in which he asked his students to toss a coin repetitively and mark down the results on a piece of graph paper. If the coin toss came up heads then they noted an increase, if tails then a decrease. After numerous coin tosses the chart constructed closely resembled the movements of a share price. The Princeton professor then showed the piece of graph paper to a Technical Analyst and asked him to give a forecast. The unsuspecting analyst assumed it revealed the price fluctuations of a security, and proceeded to analyse the chart and make recommendations. He concluded the share was about to go up and advised to buy right now. When Burton Malkiel told him the chart didn’t show the movements of a share price, but was actually the results of coin tosses the analyst was understandably very sore. However, to Malkiel it proved that technical analysis was a spurious practice and that markets moved randomly*.
Anyone who looks at the daily chart of the AUD/USD will see long series of green up- days, with sequences of 4, 5 or 6 green candles in a row. Compared to other securities the AUD/USD seems particularly prone to trending strongly. In fact since 2001 it has risen a staggering 122% from an all time low of 0.47750 to recent all time highs of 1.0582. Surely, given Malkiel’s experiment, this sort of bias to the upside would be unlikely to occur from the results of a toss of coin? If indeed financial market’s move randomly wouldn’t the price be expected to ‘revert to mean’ over time? Isn’t that also the theoretical underpinning of the sage Wall Street advice to ‘buy low and sell high’? If that is so how does this explain the Aussie’s relentless rise?
In this article we ask whether there is a significant bias towards a prevalence of up-days in AUD/USD or whether the random walkers are correct and the Aussie’s rise can be explained as a purely chance occurrence. This is part of a long standing debate between the school of thought who believe the art of technical analysis – or trend following – is of considerable merit in predicting market change and reverent critics like Malkiel, who refute the effectiveness and accuracy of this forecasting method. (more…)