From the above, it follows that the size (capitalization, trading volume) of the spot
market is an important factor towards the maximization of the participants’
profitability. Spot market trading activity is positively influenced by the capitalization
of the corresponding derivative market through arbitrage and/or hedging
opportunities. Thus, investors with a long spot position would like to write covered
calls or buy protective puts in order to hedge their positions. Moreover, the highly
capitalized stocks with large trading volume are more attractive to investors because
these stocks are more liquid and provide lower transaction costs. Hence, large firms are
better candidates for listing.
Moreover, since volatility is embedded in the pricing formulation through
financial leverage it is expected that high volatility shares are better candidates for
Derivatives
listing strategy
309
derivative markets. This argument is strengthened by the fact that the implied
volatility is traded as a separate asset and is directly evaluated (volatility indices) in
stock exchanges. Thus, derivative markets provide the financial vehicles which
incorporate in an efficient way, high level volatility products, resulting in higher levels
of trading volumes for stocks with higher levels of volatility. In this direction, risk
averters should be interested in high volatility stocks, where the basis risk would be
eliminated more effectively. Similarly, the risk-seeking investors would prefer options
on underlying assets, high volatility shares, because they are attracted by volatile
products in order to arbitrage away any short run imbalances. In all cases the level of
stocks’ volatility should be a determinative factor for derivatives listing strategy.
On the other hand the regulatory authorities of the derivatives exchanges would be
concerned with the long run stability of the financial system. This could be achieved by
both credit risk considerations and managerial characteristic issues, such as corporate
governance provisions. In the first case, it is expected that shares with low default
probabilities are more recognized and should be more attractive for derivative listing,
while in the second case, firms with higher degrees of freedom in their management
boards (shareholder-friendly firms) should be more eligible candidates for derivative
exchanges. Corporate governance provisionsmaycontributetowards this aim, since they
are negatively related to the level ofabnormal returns, asBebchuket al. (2004)andToudas
and Karathanassis (2007) argued. According to the afore-mentioned literature, there
exists a relationship between abnormal excess returns and the corporate governance
provisions. Therefore, it would be very interesting to investigate the role of managerial
characteristics in the derivatives listing process, since in a more flexible management
board the expected abnormal returns are damped down with many implications for
volatility. The latter argument is necessary for exchanges in order for them to develop
strong and reliable customer base and to reduce the probability of failure in the face of
unanticipated financial socks. The above discussion enables us to determine those
important factors that should be considered further in our analysis. These factors are:
trading volume, capitalization, volatility, creditworthiness and a variable representing
corporate governance provision index.
4. Data and econometric methodology
Our sample consists of 60 stocks from the FTSE-20 and FTSE-40 stock indices of the
Athens stock exchange. The dataset is grouped into the control and the derivatives
samples. The derivative group consists of the shares that are traded in the ADEX. The
control group consists of the shares of the abovementioned financial indices which are
not traded in the ADEX. As regards the volatility of share prices is modeled through
the ARCH (Engle, 1982) and the GARCH (Bollerslev, 1986) processes:
1t ¼ zt · ffihffiffitffi p ; zt : Nð0; 1Þ or 1t : Nð0; htÞ where
ht ¼ a0 þa1 · 12
t21 þb1 · ht21
ð1Þ
where, 1t stands for the residuals of a linear filter of share returns while the ht
represents the volatility specification of the GARCH(1,1) model.
For the credit risk quantification we apply the Merton (1974) methodology.
According to this methodology the stockholder position (E) is considered as a call
option with underlying asset the firm’s assets, as shown in the following formulas: