Determinants of the implied volatility function on the Italian Stock Market.

This paper describes the implied volatility function computed from options on the Italian stock market index between 1995 and 1998 and tries to find out potential explanatory variables. We find that the typical smirk observed for S&P500 stock index characterizes also Mib30 stock index. When potential determinants are investigated by a linear Granger Causality test, the important role played by option's time to expiration, transacted volumes and historical volatility is detected. A possible proxy of portfolio insurance activity does poorly in explaining the observed pattern. Further analysis shows that the dynamic interrelation between the implied volatility function and some determinants could be, to a certain extent, non-linear.

Volatility and the Term Structure: Evidence from Interest Rate Derivatives

Recent evidence on bond markets suggests that there are risk factors underlying changes in interest rate derivatives prices that are independent of those underlying shifts in the yield curve. The presence of unspanned factors seems puzzling because derivatives are based on the underlying interest rates. This paper shows that the factors extracted from interest rate derivatives prices are essential in forecasting yields out-of-sample, despite being poorly related to movements in the yield curve. More specifically, we bring in information about the term structure of implied volatility from derivatives data and we use it to model the yield curve as a six-dimensional parameter dynamic system. The forecasts generated by our model appear more accurate than various standard benchmark forecasts. Moreover our investigation proves to be interesting with respect to the extant literature, because of a higher data frequency and a longer sample period. As a by-product of our analysis, we obtain forecasts of volatility that can be useful for derivatives pricing and hedging purposes. Finally, our results are especially important in light of the general failure of affine term structure models for the purpose of forecastingterm structure, volatility.

Order Submission Strategies and Information: Empirical Evidence from the NYSE

We investigate the role of asymmetric information in affecting order submission strategies. Order aggressiveness depends on the state of the order book and on the asset dynamics. We find that the most important determinants are the depth on the same side of the book and a momentum indicator. When we focus on specific situations characterized by higher probability of information-based trading, we find that orders are less aggressive, suggesting strategic behavior of informed traders. This conjecture is supported by a different response to changes in the investor's information set and by a stronger price impact of less aggressive orders.Order Aggressiveness, Informed Trading, Order Flow

Short-Selling Bans around the World: Evidence from the 2007-09 Crisis

Most stock exchange regulators around the world reacted to the 2007-2009 crisis by imposing bans or regulatory constraints on short-selling. Short-selling restrictions were imposed and lifted at different dates in different countries, often applied to different sets of stocks and featured different degrees of stringency. We exploit this considerable variation in short-sales regimes to identify their effects with panel data techniques, and find that bans (i) were detrimental for liquidity, especially for stocks with small market capitalization, high volatility and no listed options; (ii) slowed down price discovery, especially in bear market phases, and (iii) failed to support stock prices, except possibly for U.S. financial stocks.short selling, ban, crisis, liquidity, price discovery.

Resolving Macroeconomic Uncertainty in Stock and Bond Markets

We establish an empirical link between the ex-ante uncertainty about macroeconomic fundamentals and the ex-post resolution of this uncertainty in financial markets. We measure macroeconomic uncertainty using prices of economic derivatives and relate this measure to changes in implied volatilities of stock and bond options when the economic data is released. We also examine the relationship between our measure of macroeconomic uncertainty and trading activity in stock and bond option markets before and after the announcements. Higher macroeconomic uncertainty is associated with greater reduction in implied volatilities. Higher macroeconomic uncertainty is also associated with increased volume in option markets after the release, consistent with market participants waiting to trade until economic uncertainty is resolved, and with decreased open interest in option markets after the release, consistent with market participants using financial options to hedge macroeconomic uncertainty. The empirical relationships are strongest for long-term bonds and weakest for non-cyclical stocks.

The Effects of Macroeconomic News on Beliefs and Preferences: Evidence from the Options Market

We examine the effect of regularly scheduled macroeconomic announcements on the beliefs and preferences of participants in the U.S. Treasury market by comparing the option-implied state-price density (SPD) of bond prices shortly before and after the announcements. We find that the announcements reduce the uncertainty implicit in the second moment of the SPD regardless of the content of the news. The changes in the higher-order moments, in contrast, depend on whether the news is good or bad for economic prospects. Using a standard model for interest rates to disentangle changes in beliefs and changes in preferences, we demonstrate that our results are consistent with time-varying risk aversion in the spirit of habit formation.Applicationoption-implied State Price Densities; macroeconomic news; risk aversion

Introduzione all'analisi tecnica.

L'analisi tecnica si configura come uno degli approcci alla rappresentazione della dinamica dei mercati finanziari, alternativi rispetto ai modelli classici proposti dalla teoria finanziaria, che si avvale dell'osservazione di fenomeni empirici spesso trascurati dai modelli tradizionali. Il presente tech report ha l'obiettivo di delineare un quadro generale della disciplina, partendo dai presupposti per discutere successivamente diverse categorie di strumenti d'analisi; quanto presentato è propedeutico all'analisi, svolta in un successivo tech report, del valore informativo dell'analisi tecnica e delle sue relazioni con l'efficienza dei mercati finanziari.

Determinants of the implied volatility function on the Italian Stock Market

This paper describes the implied volatility function computed from options on the Italian stock market index between 1995 and 1998 and tries to find out potential explanatory variables. We find that the typical smirk observed for S&P500 stock index characterizes also Mib30 stock index. When potential determinants are investigated by a linear Granger Causality test, the important role played by option's time to expiration, transacted volumes and historical volatility is detected. A possible proxy of portfolio insurance activity does poorly in explaining the observed pattern. Further analysis shows that the dynamic interrelation between the implied volatility function and some determinants could be, to a certain extent, non-linear.Options, implied volatility, smile.

Flight-to-Quality or Flight-to-Liquidity? Evidence From the Euro-Area Bond Market

Do bond investors demand credit quality or liquidity? The answer is both, but at different times and for different reasons. Using data on the Euro-area government bond market, which features a unique negative correlation between credit quality and liquidity across countries, we show that the bulk of sovereign yield spreads is explained by differences in credit quality, though liquidity plays a non-trivial role especially for low credit risk countries and during times of heightened market uncertainty. In contrast, the destination of large flows into the bond market is determined almost exclusively by liquidity. We conclude that credit quality matters for bond valuation but that, in times of market stress, investors chase liquidity, not credit quality.

Pricing Liquidity Risk with Heterogeneous Investment Horizons

We develop a new asset pricing model with stochastic transaction costs and investors with heterogenous horizons. Short-term investors hold only liquid assets in equilibrium. This generates segmentation effects in the pricing of liquid versus illiquid assets. Specifically, the liquidity (risk) premia of illiquid assets are determined by the heterogeneity in investor horizons and by the correlation between liquid and illiquid assets. We estimate our model for the cross-section of U.S. stocks and find that it fits average returns substantially better than a standard liquidity CAPM. Allowing for heterogenous horizons also leads to much larger estimates for the liquidity premia