• Korea Real Estate Review
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• v.28 no.2
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• pp.21-34
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• 2018

The purpose of this study is to investigate the effect of macro-finance variables on the correlation between the housing and stock markets because understanding the nature of time-varying correlations between different assets has important implications on portfolio allocation and risk management. Thus, we adopted the AG-DCC GARCH model to obtain time-varying, conditional correlations. Our sample ranged from January 2004 to November 2017. Our empirical result showed that the coefficients on asymmetric correlation were significantly positive, implying that correlations between the housing and stock markets were significantly higher when changes in the housing price and stock returns were negative. This finding suggested that the housing market has less hedging potential during a stock market downturn, when such a hedging strategy might be necessary. Based on the regression analysis, we found that the term spread had a significantly negative effect on correlations, while the credit spread had a significantly positive effect. This result could be interpreted by the risk premium effect.

• Asia-Pacific Journal of Business
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• v.14 no.3
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• pp.187-204
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• 2023

Purpose - This study deals with the manager's overconfidence and stock price delay, and verified whether the stock price delay phenomenon changes as the overconfidence increases. Design/methodology/approach - Manager overconfidence means that managers have over confidence in their positions or abilities, and was measured according to Schrand and Zechman (2012). Stock price delay is a phenomenon in which information of company is not immediately reflected in the stock price, but is reflected over time, and was measured by the method suggested in a study by Hou and Moskowitz (2005). The analysis subjects used in this study are companies listed on the KOSPI market between 2011 and 2019, and the final sample is 5,509 company-years. Findings - As a result of the verification, it was shown that the stock price delay decreased as the manager's overconfidence increased, and this effect was amplified as the foreign shareholder's share ratio increased and the number of follow-up financial analysts increased. This means that as the manager's overconfidence increases, he actively provides high-quality information to the capital market. In addition, as a result of subdividing the manager's overconfidence into the investment and capital raising aspects, the capital raising aspect has a significant effect on reducing stock delays. This can be interpreted as the fact that managers with overconfident tendencies have a greater incentive to satisfy investors' information needs. Research implications or Originality - In previous studies, the characteristics of managers with strong overconfidence have both positive and negative aspects. The results of this study are significant in that they clearly demonstrated the positive aspect through the market variable of stock price delay, and it is expected to help capital market stakeholders understand the characteristics of managers with a strong propensity for overconfidence.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.429-442
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• 2015

Volatility forecasting in financial markets is an important issue because it is directly related to the profit of return. The volatility is generally modeled as time-varying conditional heteroskedasticity. A generalized autoregressive conditional heteroskedastic (GARCH) model is often used for modeling; however, it is not suitable to reflect structural changes (such as a financial crisis or debt crisis) into the volatility. As a remedy, we introduce the Markov regime switching GARCH (MRS-GARCH) model. For the empirical example, we analyze and forecast the volatility of the daily Korea Composite Stock Price Index (KOSPI) data from January 4, 2000 to October 30, 2014. The result shows that the regime of low volatility persists with a leverage effect. We also observe that the performance of MRS-GARCH is superior to other GARCH models for in-sample fitting; in addition, it is also superior to other models for long-term forecasting in out-of-sample fitting. The MRS-GARCH model can be a good alternative to GARCH-type models because it can reflect financial market structural changes into modeling and volatility forecasting.

• Convergence Security Journal
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• v.15 no.3_2
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• pp.83-93
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• 2015

In this research, we used KOSPI, KOSDAQ and a stock price of Information Security related Company - S1, Ahnlab, Suprema, Raonscure and Igloosecurity. From August 2010 to July 2014, that is during 208 weeks(4 years), we had grasped index and stock price trend. Also we had attempted various Empirical analysis - Basic statistics of Security related Stock, Analysis of variance, Correlation analysis and Weekly Rate of Rise trends. The first purpose of this research is to see correlation between Security related Company and KOSPI, KOSDAQ. The second purpose of this research is to analyze whether stock items have investment value or not while watching features of flow of stock price per item. We expect possibility and merit of investment when we suppose Security industry's high potential to grow. It seems that Security related Company deserves to be invested. We expect investment for Security related Company that has high possibility of growing will create high yields compared to Market yields.

• The Journal of Industrial Distribution & Business
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• v.9 no.6
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• pp.49-55
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• 2018

Purpose - This paper examines the effect of related party transactions on crash firm-specific stock price crash risk. Ownership of a typical Korean conglomerate is concentrated in a single family. In those entities, management and board positions are often filled by family members. Therefore, a dominant shareholder can benefit from related party transactions. In Korea, firms have to report related party transactions in financial statement footnotes. However, those are not disclosed in detail. The more related party transactions are the greater information risk. Thus, companies with related party transactions are likely to experience stock price crashes. Research design, data, and methodology - 2,598 firm-year observations are used for the main analysis. Those samples are from TS2000 database from 2009 to 2013, and the database covers KOSPI-listed firms in Korea. The proxy for related party transactions (RTP) is calculated by dividing total transactions to the related-party by total sales. A dummy variable is used as a dependent variable (CRASH) in the regression model. Logistic regression is used to explain the relationship between related party transactions and crash risk. Then, the sample was separated into two groups; tunneling firms and propping firms. The relation between related party transactions and crash risk variances with features of the transaction were investigated. Results - Using a sample of KOSPI-listed firms in TS2000 database for the period of 2009-2013, I find that stock price crash risk increases as the trade volume of related-party transactions increases. Specifically, I find that the coefficient of RPT is significantly positive, supporting the prediction. In addition, this relationship is strong and robust in tunneling firms. Conclusions - The results report that firms with related party transactions are more likely to experience stock price crashes. The results mean that related party transactions increase the possibility of future stock price crashes by enlarging information asymmetry between controlling shareholders and minority shareholders. In case of tunneling, it could be seen that related party transactions are positively associated with stock crash risk. The result implies that the characteristic of the transaction influences crash risk. This study is related to a literature that investigates the effect of related party transactions on the stock market.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.379-392
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• 2005

The size of state in Korea is like Israel, this country's venture capital is ruled by government. This venture capital's character is below: the concentration on research of venturer affect positively at quality of products. This paper lies with venture capital's risk character & performance. The results show that Korean venture capitals have lager unsystematic risk than systematic risk, which implies they specialize in specific business and/or regional areas instead of diversification. The Sharpe & Jensen measures reveal that the performances of Korean venture capitals are very low relative to even the market portfolio(Kospi) and Kosdaq Venture Index. Contrary to this, Venture firm's performance according to Entrepreneurship will cause to push up stock price.

• The KIPS Transactions:PartB
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• v.11B no.2
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• pp.207-212
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• 2004

This paper presents a reinforcement learning framework for stock trading systems. Trading system parameters are optimized by Q-learning algorithm and neural networks are adopted for value approximation. In this framework, cooperative multiple agents are used to efficiently integrate global trend prediction and local trading strategy for obtaining better trading performance. Agents Communicate With Others Sharing training episodes and learned policies, while keeping the overall scheme of conventional Q-learning. Experimental results on KOSPI 200 show that a trading system based on the proposed framework outperforms the market average and makes appreciable profits. Furthermore, in view of risk management, the system is superior to a system trained by supervised learning.

• Annual Conference of KIPS
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• 2014.04a
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• pp.967-970
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• 2014

인터넷 게시판이나 트위터 같은 온라인 매체는 쉬운 접근성과 실시간 특성으로 어떤 사건에 대한 사용자들의 반응이 즉각적으로 나타난다. 또한, 실시간으로 엄청난 양의 데이터가 생성되고 있어 이 데이터를 잘 분석한다면 실제 사회에서 나타나는 다양한 현상들에 대해 파악할 수 있다. 최근 주식 시장에서도 이러한 온라인 데이터들을 분석하여 주가 변동이나 주식 시장 상황을 이해하려는 연구가 시도되고 있다. 이 논문에서는 주식 토론방의 게시물과 주가 사이에 어떤 상관관계가 있는지를 분석하고, 이를 이용한 주식 투자 종목 추천 시스템을 제안하고자 한다. 먼저 주가와 주식 토론방 게시물들 사이의 상관관계를 분석하기 위해서 KOSPI200에 속한 회사 중 55개의 회사를 대상으로 주가와 주식 토론방 게시물을 분석하였다. 2008년부터 2013년까지 6년 동안 각 회사의 주가와 게시물의 상관관계를 분석한 결과 개별 주가와 게시물 수 사이에는 특별한 상관관계가 나타나지 않았다. 하지만 주가와 게시물 수의 상관관계가 높을수록 주식 수익률이 높은 경향을 보였다. 이 논문에서는 주가와 게시물 수의 상관관계 정보를 이용한 투자 종목 추천 알고리즘을 제안하였고, 모의투자 실험을 통해 제안 방법의 효율성을 보였다. 2008년 1월부터 2013년 12월까지의 주가와 주식 토론방 데이터를 이용한 모의투자 실험에서 제안 방법으로 구성한 포트폴리오의 1개월 평균 수익률은 약 1.82%로, 주식 네트워크 특성을 이용한 기존 방법보다 약 0.64% 높은 수익률을 보였다. 또한, 마코위츠의 효율적 포트폴리오와 KOSPI200 수익률보다 각각 약 0.85%와 1.48% 높게 나타났다.

• Journal of Industrial Convergence
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• v.19 no.5
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• pp.13-19
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• 2021

In this study, the relationship between R&D investment and firm value was approached from ESG's G(governance) perspective to verify the moderating effect of the corporate governance and ownership structure. To this end, a panel analysis was conducted on a total of 2,825 samples of 405 manufacturing companies listed on the KOSPI market during 2013~2020. The main analysis results are as follows. First of all, we found that R&D investment has a negative impact on firm value, at least in the short term, and that these relationships are moderated by corporate governance and ownership structure. When professional CEO with high level of expertise in business and management does lead R&D investment, the negative impact of R&D investment on firm value is mitigated compared to owner-manager. Also, the stronger the power of outside blockholders, the more transparent the management and disclosure of information, alleviating the information asymmetry between internal and external shareholders, which mitigates the negative impact of R&D investment on firm value. The findings suggest that the factors of ESG may not only have a direct impact on firm value, but also have a moderating effect on firm value.

• Asia-Pacific Journal of Business
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• v.12 no.2
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• pp.115-129
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• 2021

Purpose - This study aimed to clarify the effects of tax investigation probability on accounting transparency in KOSDAQ firms by using financial statement. In particular, it was analyzed whether the characteristics of a firm's listed market have a discriminatory effect on the relationship between the tax investigation selection rate (or detection rate) and earnings management. Design/methodology/approach - This paper examines analyzed the effect of tax investigation of the National Tax Service on the earnings management. The sample includes 9,603 firms listed on KOSPI and KOSDAQ from 2011 to 2018, all of which are manufacturing firms. This study conducted correlation and multiple regression analyses to verify the relationship between tax investigation probability and earnings management. The possibility of a tax investigation is the selection rate and the detection rate, and the profit adjustment was estimated at discretionary amount. Findings - As a result of empirical analysis, both firms listed on KOSPI and KOSDAQ markets showed that the higher the tax investigation rates, the more significant the possibility of reducing the earnings management of discretionary accruals. Additionally it was found that in KOSDAQ markets firms, the tax investigation detection rates had a signigicant nagative effect on discretionary accruals. Research implications or Originality - It can be interpreted that firms with a high rates of receiving a tax investigation decrease earnings management consideration of expenses such as additional tax amount due to the tax audit or a decline in corporate image.