An empirical comparison of stock market bubbles

Financial asset bubbles occur due to systematic and continuous differences between fundamental and market values. Due to high growth periods and foreign capital inflows, bubbles are also seen in stock market indexes, especially in emerging market economies. This study analyzes the existence of bubbles in BIST100, IDX COMPOSITE, BOVESPA, MDEX, NIFTY 50, SHANGAI, and S&P 500 stock markets for the period 2009:01-2021:06. RADF, SADF, and GSADF tests are applied to detect bubbles on stock market closing prices. In addition, the emergence and demise dates of the bubbles are determined by employing the date-stamping method. The GSADF test gives more effective results and determines bubbles with different durations in all stock markets, except the S&P 500. The results reveal that the most inefficient market is IDX COMPOSITE, and S&P 500is the most efficient market. The analysis includes the S&P 500, the world's most liquid and most prominent stock market, for comparison. In this respect, bubbles occur more in emerging market exchanges. The findings also confirm the validity of the rational bubble law.

Can Adaptive Market Hypothesis Explain the Existence of Seasonal Anomalies? Evidence from Dhaka Stock Exchange, Bangladesh

This paper examines the behavior of seasonal anomalies in Dhaka Stock Exchange (DSE) of Bangladesh and whether the time varying nature of the anomalies is in line with Adaptive Market Hypothesis (AMH). With this aim the research investigated whether the changes in market conditions, for example: up and down market states, stock market bubbles and crashes, initiation of automated trading system and circuit breaker system can affect the behavior of calendar anomalies and therefore, can provide justification for the seasonal patterns in DSE. To achieve the stated objectives, this study utilizes daily general index values of DSE from 1993 to 2018, with GARCH (1,1) model, Markov switching model, subsample analysis and rolling window analysis. The findings support the existence of AMH at DSE in the form of time-varying nature of seasonal anomalies. However, not all seasonal anomalies examined in the study were found to grow weaker over time. The most important finding of this study is that the investors in emerging stock markets, for example DSE, may not learn from the past investment experiences and show the adapting ability towards changed market conditions in the same manner like the investors in a developed market.

Fundamental factors of techno-economic cyclicity

The paper examines the phenomenon of stages in technical and economic development in the context of the theory of technological paradigm. On the basis of a critical rethinking of the approaches of Dosi, Perez, Glazyev et al., the marxist tendency of the rate of profit to fall, as well as an empirical analysis of the US economy, the authors built an econometric model that makes it possible to determine the factors that affect both the change of technological structures themselves and their phases. The incentive that pushes capital to the path of investment in new technologies is the dynamics of the rate of return, which tends to decline and stagnate at this stage. After the new technology was mastered by national producers, and the concentration of capital created national leaders with sufficient competitiveness. foreign economic relations between countries are intensifying, which expresses competition for the development of new markets. The growing rate of return is pushing investors to capitalize on it in the form of further investment in industries where new technology can increase the return on capital. At the same time, this creates the prerequisites for overaccumulation, which is expressed in a gradual drop in the marginal profitability in production, which directs capital to the financial sector. The financialization of the economy and the formation of stock market bubbles are taking place. After their collapse, the economy enters the stage of a fall in the average rate of profit, which again starts the process of searching for a new revolutionary technology that can ensure an increase in labor productivity. The research results make it possible to more fully explain the reasons for the change in the phases of technological orders, as well as predict these processes.

Fractal Characteristics, Multiple Bubbles, and Jump Anomalies in the Chinese Stock Market

To consider the jump problem of the Chinese stock market, this paper takes the CSI 300 Index from April 2005 to November 2015 as the research object, uses the rescaled range analysis (R/S analysis) method to examine the fractal characteristics of the Chinese stock market in the past ten years, and deduces the possibility of multiple bubbles in the Chinese stock market. Based on this, combined with the log-periodic power law (LPPL) model, the stock market bubbles are identified in different periods. The results show that China’s stock market has some anomalies in terms of positive bubbles, negative bubbles, and reverse bubbles, as well as the cross occurrence of reverse-negative bubbles. Besides, through a comparison with the major foreign stock markets, it is found that the fluctuation range of the Chinese stock market is much larger than that of the Dow Jones Industrial Average and the FTSE 100 indices in the same period and there are also more types of multibubbles, which is a connotative anomaly that makes the Chinese stock market different from other major stock markets. Furthermore, the bubble phenomenon in the Chinese stock market during the periods of 2005/4–2007/10 and 2015/6–2015/11 is studied, and it is found that there is a jump anomaly in the Chinese stock market. Finally, based on the above empirical analysis and the current state of the stock market, this paper provides some suggestions for improving the mechanism of the Chinese stock market.