Alex Plastun is Professor at the Chair of International Economics in the Sumy State University (SSU). Before joining the SSU, he was a trader and analyst in several investment companies including Admiral Markets Ltd, ForexService Ltd., MTrading, Option24 and others. He still trades in the different financial markets using his own trading strategies. Professor Plastun tries to reconcile his experience as a trader with the academic theory and is constantly searching for market inefficiencies. Address: https://mev.biem.sumdu.edu.ua/en/employees_of_nnibt/plastun-oleksij-leonidovych
This paper develops a new pair trading method to detect inefficiencies in exchange rates movement... more This paper develops a new pair trading method to detect inefficiencies in exchange rates movements and arbitrage opportunities using a convergence/divergence indicator (CDI) belonging to the oscillatory class. The proposed technique is applied to 11 exchange rates over the period 2010–2015, and trading rules based on CDI signals are obtained. The CDI indicator is shown to outperform others of the oscillatory class and in some cases (for EURAUD and AUDJPY) to generate profits. The suggested approach is of general interest and can be applied to different financial markets and assets.
Efficient market hypothesis fails from time to time. There are many reasons why it happens. We wi... more Efficient market hypothesis fails from time to time. There are many reasons why it happens. We will try to concentrate on one of them – force-majeure events – situations when something important happens unexpectedly. In this case market simply can’t absorb information in one moment. So for some period of time it becomes inefficient and stays inefficient until new information will not be included by the market. Such situations give us possibility to predict the market’s behavior. This is our intuitive assumption. To confirm or refuse it we will analyze the reaction of financial markets to the biggest force-majeure events during last 20 years. Also we will try to develop a trading strategy based on financial market’s reaction to force- majeure events.
This paper examines the short-term price reactions after one-day abnormal price changes on the Uk... more This paper examines the short-term price reactions after one-day abnormal price changes on the Ukrainian stock market. The original method of abnormal returns calculation is examined. We find significant evidence of overreactions using the daily data over the period 2008-2012. Our analysis confirms the hypothesis that after an abnormal price movement the size of contrarian price movement is usually higher then after normal (typical) daily fluctuation. Comparing Ukrainian data with the figures from US stock market it is concluded that the Ukrainian stock market is less efficient which gives rise to opportunities for extra profits obtained from trading based on contrarian strategies. Based on results of the research we also recommend some rules of trading on short-term market overreactions.
This paper examines the behavior of financial markets efficiency during the recent financial mark... more This paper examines the behavior of financial markets efficiency during the recent financial market crisis. Using the Hurst exponent as a criterion of market efficiency we show that level of market efficiency is different for pre-crisis and crisis periods. We also classify financial markets of different countries by the level of their efficiency and reaffirm that financial markets of developed countries are more efficient than the developing ones. Based on Ukrainian financial market analysis we show the reasons of inefficiency of financial markets and provide some recommendations on their solution and thus improving the efficiency.
This paper examines long-term price overreactions in various financial markets (commodities, US s... more This paper examines long-term price overreactions in various financial markets (commodities, US stock market and FOREX). First, t-tests are carried out for overreactions as a statistical phenomenon. Second, a trading robot approach is applied to test the profitability of two alternative strategies, one based on the classical overreaction anomaly, the other on a so-called “inertia anomaly”. Both weekly and monthly data are used. Evidence of anomalies is found predominantly in the case of weekly data. In the majority of cases strategies based on overreaction anomalies are not profitable, and therefore the latter cannot be seen as inconsistent with the EMH.
This paper examines short-term price reactions after one-day abnormal price changes and whether t... more This paper examines short-term price reactions after one-day abnormal price changes and whether they create exploitable profit opportunities in various financial markets. A t-test confirms the presence of overreactions and also suggests that there is an “inertia anomaly”, i.e. after an overreaction day prices tend to move in the same direction for some time. A trading robot approach is then used to test two trading strategies aimed at exploiting the detected anomalies to make abnormal profits. The results suggest that a strategy based on counter-movements after overreactions does not generate profits in the FOREX and the commodity markets, but it is profitable in the case of the US stock market. By contrast, a strategy exploiting the “inertia anomaly” produces profits in the case of the FOREX and the commodity markets, but not in the case of the US stock market.
This paper provides some new empirical evidence on the weekend effect, one of the most recognized... more This paper provides some new empirical evidence on the weekend effect, one of the most recognized anomalies in financial markets. Two different methods are used: (i) a fractional integration technique for the estimation of the degree of integration of the series (d); (ii) a trading robot approach to examine whether or not there is such an anomaly giving rise to exploitable profit opportunities by replicating the actions of traders. The lowest orders of integration are generally found on Mondays, which can be seen as evidence for a weekend effect. However, the trading robot analysis shows that this anomaly cannot be exploited to make abnormal profits, and therefore it is not inconsistent with the Efficient Market Hypothesis (EMH).
One of the leading criticisms of the Efficient Market Hypothesis (EMH) is the presence of so-call... more One of the leading criticisms of the Efficient Market Hypothesis (EMH) is the presence of so-called “anomalies”, i.e. empirical evidence of abnormal behaviour of asset prices which is inconsistent with market efficiency. However, most studies do not take into account transaction costs. Their existence implies that in fact traders might not be able to make abnormal profits. This paper examines whether or not anomalies such as intraday or time of the day effects give rise to exploitable profit opportunities by replicating the actions of traders. Specifically, the analysis is based on a trading robot which simulates their behaviour, and incorporates variable transaction costs (spreads). The results suggest that trading strategies aimed at exploiting daily patterns do not generate extra profits. Further, there are no significant differences between sub-periods (2005-2006 – “normal”; 2007-2009 – “crisis”;2010-2011 – “post-crisis).
This paper examines persistence in the Ukrainian stock market during the recent financial crisis.... more This paper examines persistence in the Ukrainian stock market during the recent financial crisis. Using two different long memory approaches (R/S analysis and fractional integration) we show that this market is inefficient and the degree of persistence is not the same at different stages of the financial crisis. Therefore trading strategies might have to be modified. We also show that data smoothing is not advisable in the context of R/S analysis.
This note highlights how Russia uses the international academic sphere—including scientometric da... more This note highlights how Russia uses the international academic sphere—including scientometric databases, international publishers, and international organizations—as a propaganda tool to legitimize its appropriation of Ukrainian territories.
This paper develops a new pair trading method to detect inefficiencies in exchange rates movement... more This paper develops a new pair trading method to detect inefficiencies in exchange rates movements and arbitrage opportunities using a convergence/divergence indicator (CDI) belonging to the oscillatory class. The proposed technique is applied to 11 exchange rates over the period 2010–2015, and trading rules based on CDI signals are obtained. The CDI indicator is shown to outperform others of the oscillatory class and in some cases (for EURAUD and AUDJPY) to generate profits. The suggested approach is of general interest and can be applied to different financial markets and assets.
Efficient market hypothesis fails from time to time. There are many reasons why it happens. We wi... more Efficient market hypothesis fails from time to time. There are many reasons why it happens. We will try to concentrate on one of them – force-majeure events – situations when something important happens unexpectedly. In this case market simply can’t absorb information in one moment. So for some period of time it becomes inefficient and stays inefficient until new information will not be included by the market. Such situations give us possibility to predict the market’s behavior. This is our intuitive assumption. To confirm or refuse it we will analyze the reaction of financial markets to the biggest force-majeure events during last 20 years. Also we will try to develop a trading strategy based on financial market’s reaction to force- majeure events.
This paper examines the short-term price reactions after one-day abnormal price changes on the Uk... more This paper examines the short-term price reactions after one-day abnormal price changes on the Ukrainian stock market. The original method of abnormal returns calculation is examined. We find significant evidence of overreactions using the daily data over the period 2008-2012. Our analysis confirms the hypothesis that after an abnormal price movement the size of contrarian price movement is usually higher then after normal (typical) daily fluctuation. Comparing Ukrainian data with the figures from US stock market it is concluded that the Ukrainian stock market is less efficient which gives rise to opportunities for extra profits obtained from trading based on contrarian strategies. Based on results of the research we also recommend some rules of trading on short-term market overreactions.
This paper examines the behavior of financial markets efficiency during the recent financial mark... more This paper examines the behavior of financial markets efficiency during the recent financial market crisis. Using the Hurst exponent as a criterion of market efficiency we show that level of market efficiency is different for pre-crisis and crisis periods. We also classify financial markets of different countries by the level of their efficiency and reaffirm that financial markets of developed countries are more efficient than the developing ones. Based on Ukrainian financial market analysis we show the reasons of inefficiency of financial markets and provide some recommendations on their solution and thus improving the efficiency.
This paper examines long-term price overreactions in various financial markets (commodities, US s... more This paper examines long-term price overreactions in various financial markets (commodities, US stock market and FOREX). First, t-tests are carried out for overreactions as a statistical phenomenon. Second, a trading robot approach is applied to test the profitability of two alternative strategies, one based on the classical overreaction anomaly, the other on a so-called “inertia anomaly”. Both weekly and monthly data are used. Evidence of anomalies is found predominantly in the case of weekly data. In the majority of cases strategies based on overreaction anomalies are not profitable, and therefore the latter cannot be seen as inconsistent with the EMH.
This paper examines short-term price reactions after one-day abnormal price changes and whether t... more This paper examines short-term price reactions after one-day abnormal price changes and whether they create exploitable profit opportunities in various financial markets. A t-test confirms the presence of overreactions and also suggests that there is an “inertia anomaly”, i.e. after an overreaction day prices tend to move in the same direction for some time. A trading robot approach is then used to test two trading strategies aimed at exploiting the detected anomalies to make abnormal profits. The results suggest that a strategy based on counter-movements after overreactions does not generate profits in the FOREX and the commodity markets, but it is profitable in the case of the US stock market. By contrast, a strategy exploiting the “inertia anomaly” produces profits in the case of the FOREX and the commodity markets, but not in the case of the US stock market.
This paper provides some new empirical evidence on the weekend effect, one of the most recognized... more This paper provides some new empirical evidence on the weekend effect, one of the most recognized anomalies in financial markets. Two different methods are used: (i) a fractional integration technique for the estimation of the degree of integration of the series (d); (ii) a trading robot approach to examine whether or not there is such an anomaly giving rise to exploitable profit opportunities by replicating the actions of traders. The lowest orders of integration are generally found on Mondays, which can be seen as evidence for a weekend effect. However, the trading robot analysis shows that this anomaly cannot be exploited to make abnormal profits, and therefore it is not inconsistent with the Efficient Market Hypothesis (EMH).
One of the leading criticisms of the Efficient Market Hypothesis (EMH) is the presence of so-call... more One of the leading criticisms of the Efficient Market Hypothesis (EMH) is the presence of so-called “anomalies”, i.e. empirical evidence of abnormal behaviour of asset prices which is inconsistent with market efficiency. However, most studies do not take into account transaction costs. Their existence implies that in fact traders might not be able to make abnormal profits. This paper examines whether or not anomalies such as intraday or time of the day effects give rise to exploitable profit opportunities by replicating the actions of traders. Specifically, the analysis is based on a trading robot which simulates their behaviour, and incorporates variable transaction costs (spreads). The results suggest that trading strategies aimed at exploiting daily patterns do not generate extra profits. Further, there are no significant differences between sub-periods (2005-2006 – “normal”; 2007-2009 – “crisis”;2010-2011 – “post-crisis).
This paper examines persistence in the Ukrainian stock market during the recent financial crisis.... more This paper examines persistence in the Ukrainian stock market during the recent financial crisis. Using two different long memory approaches (R/S analysis and fractional integration) we show that this market is inefficient and the degree of persistence is not the same at different stages of the financial crisis. Therefore trading strategies might have to be modified. We also show that data smoothing is not advisable in the context of R/S analysis.
This note highlights how Russia uses the international academic sphere—including scientometric da... more This note highlights how Russia uses the international academic sphere—including scientometric databases, international publishers, and international organizations—as a propaganda tool to legitimize its appropriation of Ukrainian territories.
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