Testing implications of the Adaptive Market Hypothesis via computational intelligence

This study analyzes two implications of the Adaptive Market Hypothesis: variable efficiency and cyclical profitability. These implications are, inter alia, in conflict with the Efficient Market Hypothesis. Variable efficiency has been a popular topic amongst econometric researchers, where a variety of studies have shown that variable efficiency does exist in financial markets based on the metrics utilized. To determine if non-linear dependence increases the accuracy of supervised trading models a GARCH process is simulated and using a sliding window approach the series is tested for non-linear dependence. The results clearly demonstrate that during sub-periods where non-linear dependence is detected the algorithms experience a statistically significant increase in classification accuracy. As for the cyclical profitability of trading rules, the assumption that effectiveness waxes and wanes with the current market environment, is tested using a popular technical indicator, Bollinger Bands (BB), that are converted from static to dynamic using particle swarm optimization (PSO). For a given time period the parameters of the BB are fitted to optimize profitability and then tested in several out-of-sample time periods. The results indicate that on average a particular optimized BB is profitable, active and able to outperform the market index up to 35% of the time. These results clearly indicate the cyclical nature of the effectiveness of a particular trading model and that a technical indicator derived from historical prices can be profitable outside of its training period.