• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.283-286
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• 2007

This paper proposes a genetic algorithm (GA) approach to instance selection in case-based reasoning (CBR) for the prediction of Korea Stock Price Index (KOSPI). CBR has been widely used in various areas because of its convenience and strength in complex problem solving. Nonetheless, compared to other machine learning techniques, CBR has been criticized because of its low prediction accuracy. Generally, in order to obtain successful results from CBR, effective retrieval of useful prior cases for the given problem is essential. However, designing a good matching and retrieval mechanism for CBR systems is still a controversial research issue. In this paper, the GA optimizes simultaneously feature weights and a selection task for relevant instances for achieving good matching and retrieval in a CBR system. This study applies the proposed model to stock market analysis. Experimental results show that the GA approach is a promising method for instance selection in CBR.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.792-795
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• 2011

After the year of 2000, compositions of stock holders in domestic firms are rapidly changing. In domestic stock market, the proportion of market value held by foreign investors reaches over 40%. There are several blue chip companies among those where foreign investors hold more than 50% of the stocks. There are still hot debates going on about whether the increase in the number of foreign investors contributes to domestic companies. This research attempted to determine foreign ownership increases enhance firm value empirically. It has been shown that foreign ownership variable has significant positive impact on Tobin's Q of firm value variable. The result suggests that foreign ownership increases in domestic corporations positively contribute to firm value, as they monitor and keep the management transparent as an institutional investor, and they work to soothe agency problems by the managements or the large stock holders.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.589-599
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• 2009

The purposes of this study is to verify whether insider trader get the excess return using inside information. For this we divide inside traders into four groups according to their ownership: maximum shareholder, main shareholders, 5% sharehoders and executives. Also we categorize inside traders into three groups: personal investor, foreign investor and institutional investors. After insiders trade their stock, excess return is reported for 20days and the size of excess return of executives and institutional investor is larger than that of other groups. It means more strict monitoring system is needed in the domestic stock market.

• East Asian Economic Review
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• v.19 no.3
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• pp.223-241
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• 2015

This paper examines the existence of value premium in the Chinese stock markets and empirically provides its explanation. Our results suggest that the value premium does exist in the Chinese markets, and investor sophistication is significant in explaining its existence. In particular, there is supporting evidence that the value premium could be driven by individual investors, whereas stocks that are mostly held by institutional investors are value-premium free. We briefly discuss the implications of our findings.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.3
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• pp.319-326
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• 2022

This study investigates the specific and conclusive reasons why a company issues bonus shares, as well as the rationale and the best timing for bonus share issuance. The study examines Carlsberg's annual reports from 1988 to 2004 to evaluate the factors that influence bonus share payments and timing. Examine supporting evidence from other businesses as well. An analysis of Carlsberg Brewery Malaysia Berhad's bonus shares granted from its inception to 2004 found that the announcement of bonus shares would increase the company's share price. As a result, the findings suggest that bonus shares are issued to correct market asymmetry. This research supports the idea that issuing bonus shares would increase the stock price, resulting in increased liquidity. Hence, companies issue bonus shares to boost their liquidity and to convey private positive information to their shareholders. This research adds to the literature by focusing on the timing and key features of bonus share issuing. It implies that dividend policy should be customized to market imperfections. As a result, dividend policies would differ significantly between organizations based on the weights each of the imperfections has on the firm and shareholders.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.189-195
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• 2014

In this research, we investigate the relationship between volatility and the trading volumes of trader types in the KOSPI 200 index stock market, futures market, and options market. Three types of investors are considered: individual, institutional, and foreign investors. The empirical results show that the volatility of the stock market and futures market are affected by the transaction information from another market. This means that there exists the cross-market effect of trading volume to explain volatility. It turns out that the option market volatility is not explained by any trading volume of trader types. This is because the option market volatility, VKOSPI, is the volatility index that reflects traders' expectation on one month ahead underlying volatility. Third, individual investors tend to increase volatilities, whereas institutions and foreign investors tend to stabilize volatilities. These results can be used in the areas of investment strategies, risk management, and financial market stability.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.11a
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• pp.427-436
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• 2000

The prediction of stock price index is a very difficult problem because of the complexity of the stock market data it data. It has been studied by a number of researchers since they strong1y affect other economic and financial parameters. The movement of stock price index has a series of change points due to the strategies of institutional investors. This study presents a two-stage forecasting model of stock price index using change-point detection and artificial neural networks. The basic concept of this proposed model is to obtain Intervals divided by change points, to identify them as change-point groups, and to use them in stock price index forecasting. First, the proposed model tries to detect successive change points in stock price index. Then, the model forecasts the change-point group with the backpropagation neural network (BPN). Fina1ly, the model forecasts the output with BPN. This study then examines the predictability of the integrated neural network model for stock price index forecasting using change-point detection.

• International Commerce and Information Review
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• v.7 no.4
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• pp.325-349
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• 2005

One aspect of the globalization of the financial market after the 1980s is represented by the concurrent monetarization of the national stock markets. As the IR activity is regarded as a new financial productivity measure, the IR activity in the stock market is being emphasized domestically and internationally. This study analyzes domestic IR activities and compares them with foreign IR activities. Specifically the "road show", a typical IR activity, which is known to resolve the information asymmetry between the firm and the investors is analyzed to see the extent of the their value increase impact on the firm. The study employs domestic and international firms that publicly announced "road shows" after April 2004. Event studies are done to see the existence of abnormal return after the public announcement of road shows. Domestic firms were found to have positive IR impacts on the stock prices, but international firms were found to have negative IR impacts on the stock prices. Also it was found that international public announcement of the road show have stronger positive impact on the stock price than domestic public announcement. The investigation of the statistically significant difference of CAR before and after the fair public announcement enforcement rule showed that the positive CAR impact is strengthened after the adoption of the rule. The conclusion is that increase of the firm value after the road show implies that the information asymmetry is reduced by the active IR actions on the firm side. The policy implication is that we have to reassure the understanding of the role of the IR activities. Specifically Korean firms may have to encourage IR activities to share the information of the firms with the investors, which may result in the trustworthy relationship between the firms and investors.

• The KIPS Transactions:PartC
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• v.13C no.1 s.104
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• pp.63-68
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• 2006

Cyber Attacks have increased damages constantly in all over the world for several years. A survey said the cost caused by Cyber Attacks had increased 225 times from 1996 to 2003. It is very difficult to calculate the cost by the Attacks exactly but the calculating the cost of cyber attacks would be great helpful for a company to decide how much budget to spend to Information Security. In this research we could reach the conclusion : the cyber attacks has decreased the stock price of the companies, especially pure internet companies. But the stock market has not greatly impacted by the types of Cyber Attacks. Korean stock market also impacted by the Internet Destruction Accident happened Jan. 25. 2003. On the basis of this study we will recommend a policy or a regulation which force board of directors and officers of a company to have information security liability.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.533-542
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• 2021

The main objective of this article is to investigate the existence of the lunar effect during the full moon period (FM period) and the new moon period (NM period) on the selected Islamic stock market returns and volatilities. For this purpose, the Ordinary Least Squares model, Autoregressive Conditional Heteroscedasticity model, Generalised Autoregressive Conditional Heteroscedasticity model and Generalised Autoregressive Conditional Heteroscedasticity-in-Mean model are employed using the mean daily returns data between January 2010 and December 2019. Next, the log-likelihood, Akaike Information Criterion and Schwarz Information Criterion value are analyzed to determine the best models for explaining the returns and volatility of returns. The empirical results have deduced that, during the NM period, excluding Malaysia, the total mean daily returns for all of the selected countries have increased mean daily returns in contrast to the mean daily returns during the FM period. The volatility shocks are intense and conditional volatility is persistent in all countries. Subsequently, the volatility behavior tends to have lower volatility during the FM period and NM period in the Islamic stock market, except Malaysia. This article also concluded that the ARCH (1) model is the preferred model for stock returns whereas GARCH-M (1, 1) is preferred for the volatility of returns.