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This paper investigates the effects of introducing equity-linked warrants (ELWs) on the stock price, trading volume, volatility, and systematic risk (beta) by using the event study methodology. The study defines the event date as the announcement date as well as the listing date. In addition, whereas previous research has investigated only call ELWs, this study analyzes the effects of introducing both call and put ELWs.

The results provide no evidence of hedging effects of issuers before the announcement dates and information effects after the announcement dates. In addition, we can't find any significant changes of variables associated with the market completeness hypothesis near the listing dates.

However, the trading volume of the stock tends to increase in the days immediately following the listing of call ELWs, which may be due to the “informed trading effect”. The empirical results also provide support for the “diminishing short-sales restrictions” hypothesis related to the listing of put ELWs, which implies that short-sale restrictions can be reduced because put ELWs can provide investors with short positions in the underlying stock.

The option pricing model of Black and Scholes (1973) shows that an option contract is redundant in a complete market as it can be completely replicated by its underlying assets and risk free assets. However, in a real world of incomplete markets, many studies have shown that option contracts are not redundant and can affect prices and trade volume of underlying assets as they contribute to the market completeness. Thus, this paper examines whether this holds for ELWs (Equity-Linked Warrants) in Korean stock market, which are well known to have the same function as option contracts. To do this, we analyze the effects of ELW listings on underlying stocks’ prices, trade volume, and volatilities, and test whether ELWs contribute to market completeness. Using the daily trading data of 5,799 ELWs on individual stocks from December 2005 to September 2011, we find that underlying stocks show significantly positive cumulative abnormal returns (CAARs) and abnormal trade volume after ELW listing dates, implying that the ELW listing affects significantly positive effects on prices and trade volume of underlying stocks. The volatility of underlying stocks is significantly decreasing after the ELW listing. The systematic risk measured as beta, however, does not change over the event window. This result indicates that the decrease in volatility of underlying stocks comes from the decrease of unsystematic risks, and the correlations between returns of market index and underlying stocks are increasing after the ELW listing. The result that ELW listing can have significant effects on the underlying market implies that current stock market is incomplete, and thus, it is natural to ask whether ELWs can contribute to market completeness. Using the method suggested by Buraschi and Jackwerth (2001), we examine whether ELWs are necessary to replicate the pricing kernel used in asset pricing. We select risk-free asset, underlying stock and ELW as reference assets to replicate the pricing kernel, and find that the pricing kernel cannot be replicated completely without ELWs. This result implies that ELWs are not redundant financial assets and are necessary to increase the market completeness in Korean stock market.

This paper focuses on the controversy about DMA (direct market access) system that facilitates ELW (equity linked warrants) transaction. We analyze trading profit/loss and such features in accordance with the investor type by the combination of trading counts and trading amounts. Especially, our analysis centers on whether brokerages’ providing DMA system contributes to the market expansion and DMA system serves as a profit-making expedient for the investors whose trading amount is large or trading frequency is high.

Based on our empirical examination utilizing total ELW trading data from 2009 to 2011, the following implications are obtained as a result: Firstly, the growth of the ELW market mainly comes from the increased transactions by the investors accessing via DMA and there is no evidence that providing DMA system itself adds to the revitalization of overall market. Secondly, our GMM results using dummy variables confirm us that providing DMA possibly plays a critical role in making profit for the investor of large trading amount or high trading frequency. Our results support the structural problem is embedded in ELW market and DMA system intensifies such unfair game.

We examine the effects of new regulations introduced by Korean government to cool down overheated Korean ELW markets. We also investigate whether ELWs are fairly priced as noted in the previous research. The empirical findings are as follows. Firstly, ELW was more expensive than KOSPI200 option not only before but also after the introduction of the new regulations. But degrees of the overpricedness are decreased significantly with the new regulations. Secondly, we confirm the well known facts in the literature that liquidity providers get extra profits as monopolistic providers for ELWs. Thirdly, we analyze the determinants of the differences in premiums between ELW and KOSPI200 option. The trading volume is negatively correlated with premium difference, however, timeto-maturity and market share are not statistically significant. Even though it seems that the financial regulator achieve their primary purpose to control the overheated market, we find that the new regulations have almost no effects on the overpricing problem, which implies that overpricing in ELW is not related to the market inefficiency.

Conventional study on the trading pattern of investors is either done in the viewpoint of the identity of investors or analyzed on the base of investor's type, which is categorized according to the number of transactions using only restricted security company data. Dataset in this paper is extended to all ELW series and investor's type such as the LP (Liquidity Provider). High-frequency traders are categorized on the base of average number of transactions per day and average trading volume per day. We analyze their trading pattern and relationship between P/L (profit and loss) and their trading pattern. Also We develop a new measurement tool, called the holding period, to comprehend the characteristic of high frequency trading and analyze the effect of holding period on P/L of investors.

Our empirical investigation shows that, for general investors, 1) their counterparties are LP during the execution of buy low and sell high trading strategy, 2) they lose in the cumulative P/L for the intermediate transaction although their average sell price is more expensive than average buy price, 3) due to the lack of risk management technique such as stop loss, they lose in the cumulative intermediate transaction P/L although their winning ratio is higher than losing ratio. On the other hand, 1) scalpers are mainly engaged in trading index ELW market, 2) due to the appropriate execution of stop loss, they win in the cumulative P/L for the intermediate transaction although their draw ratio and trading unit price are high. Meanwhile, due to the LP's passive characteristic for the buying execution after selling, their draw ratio is very low and their buy unit price is higher than sell unit price in comparison to other investor type, and their trading pattern is negatively related to that of the other investor type. Finally we confirm that the holding period is a significant impact on P/L of general investors and scalper.

As a policy proposal, it is necessary to introduce a market maker system in the individual stock options market for activating the stock options market, which has a more competitive market structure than ELW market. In the viewpoint of financial consumer protection, education on the time value reduction of contingent claim derivatives with finite maturity is necessary.

The authors investigate the 2008-2009 short-sales ban in Korea, one of the most comprehensive and restrictive short-selling bans worldwide. The purpose of this paper is to examine: whether the ban stopped a destabilizing effect, if there was any, of short-selling activities; whether the ban improved or deteriorated the informational efficiency or the price discovery process of the stock market; and whether the ban had any impact on market liquidity.

Multiple regression; vector autoregression analysis; and generalized autoregressive conditional heteroskedasticity analysis.

The authors find no evidence that short-sales have a market-destabilizing effect and thus, restricting short-selling has a market-stabilizing effect. On the contrary, the short-selling ban is associated with an increase in return volatility and a deterioration of the price discovery process, particularly for the stocks without derivatives traded on them. The authors also find evidence of a liquidity decrease for short-sale intensive stocks. However, the evidence is inconclusive as to whether the market efficiency and liquidity changes are solely the result of the short-sales ban or the compound effects of both the ban and the concurrent progress of the financial crisis.

The literature does not provide a conclusive view on the effects of short-sales or restrictions thereof on the stock market. Also, the existing research on recent worldwide shorting bans often lack empirical scope (e.g. 32 stocks for UK; three weeks for USA). In contrast, the short-sales ban in the Korean stock market, one of the most comprehensive and restrictive short-selling bans worldwide, lasted for eight months for all the listed stocks and is still in effect for financial stocks. The authors find no evidence that short-sales have a market-destabilizing effect and thus, restricting short-selling has a market-stabilizing effect.