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This study examines the forecasting ability of the adjusted implied volatility (AIV), which is suggested by Kang, Kim and Yoon (2009), using the horserace competition with historical volatility, model-free implied volatility, and BS implied volatility in the KOSPI 200 index options market. The adjusted implied volatility is applicable when investors are not risk averse or when underlying returns do not follow a normal distribution. This implies that AIV is consistent with the presence of risk premia for other risk such as volatility risk and jump risk. Using KOSPI 200 index options, it is shown that the AIV outperforms other volatility estimates in terms of the unbiasedness for future realized volatilities as well as the forecasting errors.

This paper assesses the empirical performances of the continuous-time models, including constant volatility (Black and Scholes, 1973), stochastic volatility (Heston, 1993), and stochastic volatility with jumps (Bates, 1996), in FX spot and option markets. To analyze the spot market, we used the EMM (Efficient Method of Moments) methods with daily KRW/USD spot exchange rates from November 1997 through July 2009. First, the empirical results find that the Bates model highly outperforms the other modelsin explaining the dynamic behavior of KRW/USD spot exchange rates. Second, we also find that the jump components carry out an important role in generating leptokurtic properties of KRW/USD spot exchange rates, on the other hand, stochastic volatilities perform a critical role in generating skewed properties of them. To analyze the option market, we examined the daily cross-sectional prices of the KRW/USD OTC options from January 2006 through March 2010. The empirical results from the option markets confirm that the Bates model clearly outperforms the other modelsin explaining the observed patterns of implied-volatility smile or smirk.

This paper investigates ATM zero-beta straddle (i.e., ZBS) returns, one of the most widely used volatility trading strategies, and then examines the determinants of them. First, from a point of theoretical view, we find that the determinants of the ZBS returns without rebalancing are different from those with rebalancing. This means that most previous studies overlooking the return characteristics by difference of rebalancing frequency could result in misleading implications. Next, from a point of empirical view, we find that the negative excess returns are also obtained by taking a long position in ZBS on the KOSPI 200 index options, as in most other markets. Even though these negative excess returns are not strongly significant, but they are found to be closely related to the volatility risk premium.

In this paper, we examined the economic benefits of derivatives in the aspect of investment assets. Our study differs from previous studies in that it analyzed the differences in the economic benefits of derivatives between for short term investors and for long term investors, and focused on the equity linked securities (ELS) rather than plain vanilla derivatives. We found the following results from the analysis over 1 to 20 years of investment horizons for four different types of equity linked securities, including ‘Auto-callable ELS’, ‘Knock-out ELS’, ‘Digital ELS’ and ‘Reverse Convertible ELS.’ First, equity linked securities contribute to improving the performance of the optimal portfolio for most investors, except for some investors who have extremely low degrees of risk aversion. Second, these economic benefits of equity linked securities are consistently observed regardless of investment horizon. Third, investment demand for equity linked securities is higher for investors with a medium-level of risk aversion rather than for aggressive or conservative investors. In addition, equity linked securities are mainly used as substitutes for risk-free bonds rather than risky assets (i.e., stocks). Finally, most of our results are still valid even when different market environments are assumed or alternative decision rules are used to derive investors’ optimal portfolio.

This paper investigates the effect of investment horizon on the optimal portfolio choice of investors, who can access to index options market. This is to reconcile the empirical anomaly of Driessen and Maenhout (2007), which suggested that it is always optimal to short OTM puts and ATM straddles, regardless of investors’ preferences. Using the intraday data on KOSPI200 index options, one of the most actively traded options in the world, we analyze the differences in optimal choice between ‘position traders (i.e., long-term investors)’ and ‘day traders (i.e., short-term investor)’. Our main empirical findings are summarized as follows. First, short horizon investors who do not want to hold overnight option positions tend to optimally take a long position in options, whereas long horizon investors tend to hold short option positions. Second, these differences in optimal choice between short- and long-horizon investors are clearly evident in OTM puts rather than ATM straddles. Finally, our empirical findings are still valid even after considering alternative preferences structures of investors, transaction costs, different data filtering rules, and the effect of the Global financial crisis.

This study investigates the over- and under-reacting behavior of USD/KRW OTC currency option investors from the year of 2006 to 2011. Using the empirical testing models suggested by Poteshman (2001), we first find that USD/KRW OTC option investors tend to under-react to the unexpected changes in instantaneous variances, which means ‘short horizon under-reaction’. Second, we find that USD/KRW OTC option market tends to slightly over-react to a long period of mostly positive (or negative) unexpected changes in instantaneous variances during the period of before global financial crisis in 2008, We find, however, that this ‘long horizon over-reaction’ in the aforementioned period is not statistically significant. Third, we find that the market tends to significantly under-react, rather than over-react, to a long period of mostly positive (or negative) unexpected changes in instantaneous variances during the period of after global financial crisis in 2008. Finally, using the different empirical testing model (i.e., model-free approach), suggested by Jiang and Tian (2010), we also obtained the same empirical results, which strengthen the robustness of them.

This paper develops “Strategy Benchmark Index (SBI)” using KOSPI200 options data from January 2004 to March 2017, and then investigates their performances. The SBIs were constructed in the same way as those published daily by CBOE. To effectively analyze the performance of these SBIs, we classified them into four types : (1) Return enhancement SBIs (six indices), (2) Volatility trading SBIs (two indices), (3) Directional trading SBIs (two indices) and (4) Other SBIs (two indices). The return enchancement SBIs include bechmark indices tracking the performance of various covered call strategies and put writing strategies, which are generally used to increase investment returns. The volatility trading SBIs include benchmark indices tracking the performance of well-known volatility trading strategies such as butterfly spread and condor. Benchmark indices tracking the performance of various types of zero-cost collar strategies are classified into the directional trading SBIs. Our empirical results are as follows. First, the risk-adjusted performances of nine SBIs of the total twelve SBIs constructed from KOSPI200 index options has been shown to be great. Second, from a portfolio perspective, some SBIs can be helpful to improve the portfolio performance of CRRA (Constant Relative Risk Aversion) investors. These results imply that passive investment strategies with KOSPI200 index options can provide additional benefits that both equities and bonds do not provide. Third, even when we use the traditional mean-variance framework other than expected utility theory to verify the economic benefit of the SBIs, our empirical results are found to be still valid. In conclusion, our results suggest that some passive investment strategies using KOSPI200 index options would be beneficial to long term investors.

The variance risk premium defined as the difference between risk neutral variance and physical variance is one of the most crucial information recovered from option prices. It does not, however, reflect the asymmetry in upside and downside movements of underlying asset returns, and also has limitation in reflecting asymmetric preference of investors over gains and losses. In this sense, this paper decomposes variance risk premium into downside - and upside-variance risk premium, and then derives the skewness risk premium and examines its effectiveness in predicting future underlying asset returns. Using KOSPI200 option prices, we obtained the following results. First, we found out that the estimated skewness risk premium has meaningful forecasting power for future stock returns, while the estimated variance risk premium has little forecasting power. Second, by utilizing our results of skewness risk premium, we developed a profitable investment strategy, which verifies the effectiveness of skewness risk premium in predicting future stock returns. In conclusion, the empirical results of this paper can contribute to the literature in that it helps us understand why variance risk premium, in most global markets except the US market, has not been successful in forecasting future stock returns. In addition, our results showing the profitability of investment strategies based on skewness risk premium can also give important implications to practitioners.

This study examines the effects of crisis-related factors on the returns of KOSPI200 index options using a factor model, which was introduced by Constantinides, Jackwerth and Savov (2013). Three factors incorporating price jumps, changes in volatility, and volatility jumps are considered as the crisis-related factors. With the data for the period from 2004 to 2015, we find followings : First, most of the crisis-related factor premia are statistically significant, and their signs are consistent with those expected. Second, these crisis-related factors contribute to improve the understanding of the cross-sectional variation in KOSPI200 index option returns. Third, the crisis-related factor premia became much more significant after the global financial crisis in 2008. Finally, our empirical findings are robust to whether the long options and the in-the-money options are included in the sample or not, and to whether the factor premia are constrained to equal the corresponding premia estimated from the cross-section of equities.

This paper investigate the information content of implied volatilities derived from KRW/USD OTC currency options. First, we examined the explanatory power of implied volatilities in forecasting future realized volatilities of the spot exchange rates. Next, we examined the dynamic properties of volatility spreads, the difference between implied volatilities and realized volatilities, observed in KRW/USD currency option markets. Using the sample data from January 2006 through March 2010, we first find that even though the implied volatilities have a little explanatory power in forecasting future realized volatilities, they don't improve the information content of simple historical volatilities at all. Second, this paper finds that during the period before global financial crisis in 2008, the implied volatilities are consistently lower than the realized volatilities. This suggests that we cannot exclude the possibility of risk seeking behavior of the investors in KRW/USD OTC currency option markets at that time. Finally, from the comparative analysis with KOSPI 200 index options for the same sample period, we confirmed that our empirical results are uniquely observed only in KRW/USD OTC currency option markets.