• 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.

• Journal of the Korea Society of Computer and Information
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• v.29 no.5
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• pp.11-20
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• 2024

This study presents TabNet, a novel deep learning method, to enhance corporate credit rating accuracy amidst growing financial market uncertainties due to technological advancements. By analyzing data from major Korean stock markets, the research constructs a credit rating prediction model using TabNet. Comparing it with traditional machine learning, TabNet proves superior, achieving a Precision of 0.884 and an F1 score of 0.895. It notably reduces misclassification of high-risk companies as low-risk, emphasizing its potential as a vital tool for financial institutions in credit risk management and decision-making.

• The Korean Journal of Financial Studies
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• v.3 no.1
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• pp.233-265
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• 1996

We examine the impact of public and private information on price movements using the thirty DJIA stocks and twenty-one NASDAQ stocks. We find that the standard deviation of daily returns on information days (dividend announcement, earnings announcement, insider purchase, or insider sale) is much higher than on no-information days. Both public information matters at the NYSE, probably due to masked identification of insiders. Earnings announcement has the greatest impact for both DJIA and NASDAQ stocks, and there is some evidence of positive impact of insider asle on return volatility of NASDAQ stocks. There has been considerable debate, e.g., French and Roll (1986), over whether market volatility is due to public information or private information-the latter gathered through costly search and only revealed through trading. Public information is composed of (1) marketwide public information such as regularly scheduled federal economic announcements (e.g., employment, GNP, leading indicators) and (2) company-specific public information such as dividend and earnings announcements. Policy makers and corporate insiders have a better access to marketwide private information (e.g., a new monetary policy decision made in the Federal Reserve Board meeting) and company-specific private information, respectively, compated to the general public. Ederington and Lee (1993) show that marketwide public information accounts for most of the observed volatility patterns in interest rate and foreign exchange futures markets. Company-specific public information is explored by Patell and Wolfson (1984) and Jennings and Starks (1985). They show that dividend and earnings announcements induce higher than normal volatility in equity prices. Kyle (1985), Admati and Pfleiderer (1988), Barclay, Litzenberger and Warner (1990), Foster and Viswanathan (1990), Back (1992), and Barclay and Warner (1993) show that the private information help by informed traders and revealed through trading influences market volatility. Cornell and Sirri (1992)' and Meulbroek (1992) investigate the actual insider trading activities in a tender offer case and the prosecuted illegal trading cased, respectively. This paper examines the aggregate and individual impact of marketwide information, company-specific public information, and company-specific private information on equity prices. Specifically, we use the thirty common stocks in the Dow Jones Industrial Average (DJIA) and twenty one National Association of Securities Dealers Automated Quotations (NASDAQ) common stocks to examine how their prices react to information. Marketwide information (public and private) is estimated by the movement in the Standard and Poors (S & P) 500 Index price for the DJIA stocks and the movement in the NASDAQ Composite Index price for the NASDAQ stocks. Divedend and earnings announcements are used as a subset of company-specific public information. The trading activity of corporate insiders (major corporate officers, members of the board of directors, and owners of at least 10 percent of any equity class) with an access to private information can be cannot legally trade on private information. Therefore, most insider transactions are not necessarily based on private information. Nevertheless, we hypothesize that market participants observe how insiders trade in order to infer any information that they cannot possess because insiders tend to buy (sell) when they have good (bad) information about their company. For example, Damodaran and Liu (1993) show that insiders of real estate investment trusts buy (sell) after they receive favorable (unfavorable) appraisal news before the information in these appraisals is released to the public. Price discovery in a competitive multiple-dealership market (NASDAQ) would be different from that in a monopolistic specialist system (NYSE). Consequently, we hypothesize that NASDAQ stocks are affected more by private information (or more precisely, insider trading) than the DJIA stocks. In the next section, we describe our choices of the fifty-one stocks and the public and private information set. We also discuss institutional differences between the NYSE and the NASDAQ market. In Section II, we examine the implications of public and private information for the volatility of daily returns of each stock. In Section III, we turn to the question of the relative importance of individual elements of our information set. Further analysis of the five DJIA stocks and the four NASDAQ stocks that are most sensitive to earnings announcements is given in Section IV, and our results are summarized in Section V.

• The Korean Journal of Financial Management
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• v.25 no.2
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• pp.191-213
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• 2008

This study tests and reconfirms the wealth transfer of mergers and acquisitions(M&As) by examining the changes in and the relationship between shareholder and bondholder wealth after the announcements of M&As for the publicly listed firms in Korea Stock Exchange and KOSDAQ market during $1999{\sim}2006$. The change in shareholder wealth is measured by the Cumulative Abnormal Return(CAR) at the M&A announcements, and the change in bondholder wealth is calculated using the Yield Spread Change(YSC) and the change in acquiring firms' credit ratings. The empirical tests show that the CAR of 344 sample acquiring firms at the announcement is 3.59%, which confirms results of the prior research on M&As in Korean market. The average YSC for 35 sample acquiring firms between $2001{\sim}2006$ proves to be negative when we use the yield spread of firms with comparable credit ratings as a benchmark, which means that the acquiring firms' bondholders gain with the announcements of M&As. We find the same result using another benchmark-the yield spread of government bonds. The improvement in the acquiring firms' credit ratings one year after the M&As also indicates that the M&As, on average, increase bondholder wealth. Our test results are consistent with those of the existing studies on the effect of bondholder wealth after the M&As in the United States, which shows that the bondholder wealth increases after the M&As. We do not find the evidence that there is a wealth transfer from the acquiring firms' bondholders to the shareholders after the M&A announcements. Rather, this study confirms that the wealth of the acquiring firms' bondholders increases in the M&As in Korea.

• The Korean Journal of Financial Management
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• v.27 no.1
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• pp.31-62
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• 2010

This paper analyzes empirically how analysts' forecasts affected by ownership structure. This study examine a sample of 1,037~1,629 the analysts' forecasts of firms registered in Korean Stock Exchange in the period from 2000 to 2006. The empirical results are summarized as follows. First, from the analysis, companies which have higher major shareholder's holdings tend to increase earnings forecast errors and earnings forecast accuracy. Meanwhile, companies which have higher institution shareholder's holdings tend to decrease earnings forecast errors and earnings forecast accuracy. This result is in line with the view of previous works that companies with higher major shareholder's holdings look towards more of analysts' optimistic forecasts in order to maintain friendly relations with major shareholders. Because of analysts' private information use from major shareholders, earnings forecast accuracy is higher in high major shareholder's holdings firm than in high institution shareholder's holdings it. Second, this analysis is whether the minimal required selection condition of outside directors, audit committee adoption and audit quality affect the relation between ownership structure and analysts' forecasts. This result is that variables related corporate governance do not affect statically the relation between ownership structure and analysts' forecasts. The meanings of this paper is to suggest the positive relations between ownership structure and analysts' forecasts. After this, if analysts will notice forecasts of more many firms, capital market will be more efficient and this field works are plentiful. Also it will need monitoring systems not to distort market efficiency by analysts' dishonest forecasts.

• Korean journal of communication and information
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• v.19
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• pp.185-211
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• 2002

Media convergence is prevalent all over the world, and is expected to change our lives dramatically in near future. Chaos theory is a new emerging theoretical approach to various social phenomena including organization management, economic system, stock market fluctuation, and so on. This thesis is intended to explain media convergence phenomena centered on internet media using basic concepts of chaos theory such as self-organization, co-evolution, and feedback loop. The implications of this tentative study are that we can apply chaos theory to media convergence as other social or natural phenomena, and that maintaining chaos state of media system is useful for accelerating creativities, and that developing media system as an organic system to cooperate with other relevant systems is helpful for promoting life qualities, and that establishing moral order or root value is desirable for implementing communicatopia.

• KDI Journal of Economic Policy
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• v.33 no.1
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• pp.93-124
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• 2011

In this paper, we claim the asymmetric response of asset returns on the past asset returns' signs may be explained from the market behavioral portfolio choice of investors. For this, we admit the anchor and adjustment mechanism of investors which partly explains the momentum in the asset prices. We also claim the prospect theory based on the risk aversions may simultaneously work with the anchor and adjustment effect, whenever the lagged asset return was positive and investors accrued the gain. To identify these effects empirically in a threshold autoregressive model, we suppose the risk aversions inducing the volatility effect is related with the past volatility of asset returns. In application of suggested method to Korean stock and real estate markets, we found these effect exist as expected.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.159-168
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• 2008

Since the term structure of interest rates (TSIR) has longitudinal data, we should consider as input variables both time left to maturity and time simultaneously to get a more useful and more efficient function estimation. However, since the resulting data set becomes very large, we need to develop a fast and reliable estimation method for large data set. Furthermore, it tends to overestimate TSIR because data are correlated. To solve these problems we propose a mixture of weighted least squares support vector machines. We recognize that the estimate is well smoothed and well explains effects of the third stock market crash in USA through applying the proposed method to the US Treasury bonds data.

• International Journal of Human Ecology
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• v.7 no.2
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• pp.53-62
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• 2006

The purpose of this study is to examine the changes in financial structure of the self-employed brought on the economic crisis in Korea.. We use financial ratio analysis, such as income to expenditure ratio, liquidity ratio, debt ratio, and capital accumulation ratio to analyze financial well-being of self-employed households. This study used a 1997 and 1998 Korean Household Panel Study collected by Daewoo Economic Research Institute. The average amount of holding of each type of asset showed that the investment of self-employed households decreased in the banking industry and the stock market in 1998 compared to 1997. On the other hand, asset allocation in bond and real estate increased, which implied preference for a stable type of asset with the increase in uncertainty of the future and economic instability. Devaluation of real estate allowed households to easily obtain real estate and increase preference for asset allocation in real estate after the crisis. The changes in financial ratio for the year 1998 shows that such ratios as income to expenditure, liquidity, and capital accumulation, decreased compared to the year 1997. Among those ratios, the income to expenditure ratio showed the biggest decline because of reduced income of self employed households. The results implied that the income structure of the self-employed is unstable, thus the self-employed were likely to be greatly affected during the economic downturn. Earners have more average income and net assets than the self-employed. However, using financial ratios, it was found that self-employed households were more stable than employees. The results shows that the financial ratio analysis is better tool to estimate households financial status. Implications for financial educators, counselors, and planners are offered. The results will provide implications for policy makers to establish appropriate policies for the self-employed and help them financially survive.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.230-236
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• 2011

This paper proposes the possibility which the fuzzy theory can be used to improve the performance of the parabolic SAR(Stop-And-Reverse) indicator in the trading systems for stock market. The simulation results with data of the KOSPI 200 future show that the occurred number of trading signals and the false signals in the proposed fuzzy SAR indicator is less than that in the conventional SAR indicator. In the conventional SAR system, the incremental value of the acceleration factor is usually setted as 0.02 and the maximum value of the acceleration factor is usually limited as 0.2. But in the proposed fuzzy SAR system, the incremental value and the maximum value of the acceleration factor are automatically adjusted by using the fuzzy rules, which are designed based-on the difference between short-term moving average and medium-term moving average and also based-on the slope of short-term moving average.