Covered Warrants : How the Implied Volatility Changes Over Time

Abstract: Problem: Investors are dependent on the issuers’ valuation of covered warrants because the issuers also act as market makers. Hence it is crucial that the issuers value each of the five variables used in the Black & Scholes pricing formula in the same way at both the buying and selling occasion. For a covered warrant investor the most important is-sue is the volatility and how it changes over time. This thesis will therefore search for differences in changes of implied volatility between the different issuers. Purpose: The purpose of this thesis is to analyze differences and similarities between the issuers’ changes of their covered warrants implied volatility. Method: The authors have calculated the implied volatility for a sample of warrants with H&M and Ericsson as underlying assets. Black & Scholes formula has been used and this part of the thesis is made with a quantitative approach. After the implied volatility had been calculated correlation tests to the mean as well as to the stock were made. When analyzing the results the authors, in addition to the calculation, used a qualitative method by interviewing market makers. This was made in order to find better explanations to the results. Conclusions: The differences in changes of implied volatility found between different warrants were small. In general, one warrant changed in the same way as the other ones from one day to another. These results reject the rumors that single issuers adjust their implied volatility in order to make more money. When single events in form of reports were analyzed, the authors found that the issuers changed their volatility in the same way to adjust for the changed uncertainty about the stocks future price. Further, these events clarifies that the basic dynamics of implied volatility is followed by the market. The analysis of how the implied volatility changes with respect to the stock price movements indicates a negative correlation. This implies that an increase in the stock price will lower the implied volatility and vice verse.