Stock Market Forecast and Trading

Some indicators can provide a better prediction than others so that it seems logically to use the best selected ones to build a composite forecast. On the other hand, even the best indicators can fail. The questions is how to get a consistent good accuracy in predicting – by using only a few best indicators or many good ones. The answer is not obvious and, therefore, a factual comparative analysis would be needed to shed some light on this issue. This short report is based on limited statistical researches; it is an attempt to reach a certain conclusion.

About Expert Method. Apparently, the more good forecasts are taken into consideration, the more precise can be an approximation to actual value. There is Expert Method. This method can be explained by following. As example, an experimentalist shows a pen and asks a group of about 40 people to write down their estimate of the length. Then he collects notes and calculates the average number – normally it is almost 100% accurate. Why it works? Because everyone makes errors in different directions so that averaging gives a precise result.

The Details of Experiment. To find an optimal number of top performing indicators, two tests have been done – using artificial data and real market data. Artificial data allow performing forward testing with more consistent statistics. Although back-testing has been done on out-of-sample sets, it did not have the same forward-testing success every time. Forward testing showed that in average few indicators might produce less accurate prediction than many.

The researches and presented chart are made by Technical Analyzer TA-1 (the software is able to compose Neural Network forecasts of many indicators with weights accordingly to each indicator’s predictive ability).

Conclusion. The main conclusion is that relying on a couple of best indicators might yields less consistent success over a long run than using many best and good ones. However, too many is another extreme and not good. The second conclusion is that the list of best indicators is not static – it evolves depending on many factors, including market conditions and, probably, on the number of traders employing particular indicators to make their buy-sell decisions. Thirdly, if the best current top of indicators is known, here is a magic number – it is around 30. And finally, better results are possible if indicators are combined accordingly to their latest back-testing ranking.

Technical analysts use many different indicators. Not all indicators are equally good. Some of them have better predictive abilities than others at given conditions. Statistical results of the research for stocks and indexes during the last several months have showed the way to improve some regular indicators. In short, if an indicator is trend-differentially coupled with price – it demonstrates better predictive abilities than a pure indicator.

Among studied indicators are Relative Strength Index (RSI) and Moving Average Convergence/Divergence (MACD) indicators. They have been transformed to a slope of line and differentially-coupled with a price line slope. Indicators and price transformation to line slopes has been performed using Least Squares Linear Regression within a sliding 10-day period (moving window). A comparative analysis of indicators’ predictive abilities showed that these two coupled ones are better than around 90% of all other (57) the most popular indicators.

The chart below shows an example of such forecast:

The research results presented here have been calculated using a feature of Technical Analyzer TA-1 (TA). Except analyzing chart with indicators and historical data, TA enables to perform a 10-day forecast using Artificial Neural Network. The calculations can be done on the basis of one selected technical indicator or all available. If all indicators used, TA decides how much weight should be assigned for each indicator’s forecast in a composite result by using back-testing for particular market conditions and a specific stock. Each weight is proportional to a predictive ability of a corresponding technical indicator.

This week a stock market rally was driven mostly by news and may last more days ahead. Concerning technical analysis prediction, the chart below can give a clue of S&P-500 index forecast for the next two weeks of November, 2010. According to this forecast the uptrend may continue only 2-3 days and then it can reverse to downside.

This forecast composed from many technical indicators with weights accordingly to the predictive ability of each indicator. It is a short-term (10 trading days) forecast using Neural Network. The used software tool is Investment Analyzer InvAn-4.