Asymmetric ACD models: Introducing price information in ACD models

This paper proposes an asymmetric autoregressive conditional duration (ACD) model, which extends the ACD model of Engle and Russell (1998). The asymmetry consists of letting the duration process depend on the state of the price process. If the price has increased, the parameters of the ACD model can differ from what they are if the price has decreased. The model is applied to the bid-ask quotes of two stocks traded on the NYSE and the evidence in favour of asymmetry is strong. Information effects (Easley and O'Hara 1992) are also empirically relevant. As the model is a transition model for the price process, it delivers `market forecasts' of where prices are heading. A trading strategy based on the model is implemented using tick-by-tick data.While remaining responsible for any error in this paper, the authors would like to thank R. Anderson, G. Le Fol, C. Gouriéroux, J. Jasiak, W. Pohlmeier, A. Roell, O. Scaillet, S. Wei and three anonymous referees for useful remarks and suggestions on previous versions. The authors would also like to thank A. Ruttiens from KBC-CBC for useful discussions on practical issues related to trading. Support of the European Commission Human Capital and Mobility Program through the network `Econometric inference using simulation methods' is gratefully acknowledged. This paper presents research results of the Belgian Program on Interuniversity Poles of Attraction initiated by the Belgian State, Prime Minister's Office, Science Policy Programming. The scientific responsibility is assumed by the authors.     

An International Analysis of Earnings, Stock Prices and Bond Yields

Abstract:  This paper assesses the contemporaneous relationship between stock prices, earnings and long-term government bond yields for a large number of countries. The time period of our data spans several decades. In a time series framework our analysis first tests the presence of a long-term contemporaneous relationship between these three variables (the so-called Fed model). Next, we assess if government bond yields play a significant role in the long-run relationship. Our empirical results question the validity of the Fed model in the sense that we show that long-term market movements are mainly driven by the earnings yield and not the differential between bond and earnings yields. As such, our analysis validates the results of Asness (2003) for a much larger collection of countries while using a dynamic time series (cointegration) framework. Finally, we also show that changes in long-term government bond yields have a short-term impact on stock prices.     

How large is liquidity risk in an automated auction market?

We introduce a new empirical methodology that models liquidity risk over short time periods for impatient traders who submit market orders. Using Value-at-Risk type measures, we quantify the liquidity risk premia for portfolios and individual stocks traded on the automated auction market Xetra. The specificity of our approach relies on the adequate econometric modelling of the potential price impact incurred by the liquidation of a portfolio. We study the sensitivity of liquidity risk towards portfolio size and traders' time horizon, and interpret its diurnal variation in the light of market microstructure theory.

---

Commonalities in the order book

This paper uses data from one of the most important European stock markets and shows that, in line with predictions from theoretical market microstructure, a small number of latent factors captures most of the variation in stock specific order books. We show that these order book commonalities are much stronger than liquidity commonality across stocks. The result that bid and ask side as well as the visible and hidden parts of the order book exhibit quite specific dynamics is interpreted as evidence that open order book markets attract a heterogeneous trader population in terms of asset valuations and impatience. Quantifying the informational content of the extracted factors with respect to the evolution of the asset price, we find that the factor information shares are highest (about 10%) for less frequently traded stocks. We also show that the informational content of hidden orders is limited.

The information content of implied volatility in agricultural commodity markets

In this article we compare the incremental information content of lagged implied volatility to GARCH models of conditional volatility for a collection of agricultural commodities traded on the New York Board of Trade. We also assess the relevance of the additional information provided by the implied volatility in a risk management framework. It is first shown that past squared returns only marginally improve the information content provided by the lagged implied volatility. Secondly, value‐at‐risk (VaR) models that rely exclusively on lagged implied volatility perform as well as VaR models where the conditional variance is modelled according to GARCH type processes. These results indicate that the implied volatility for options on futures contracts in agricultural commodity markets provides relevant volatility information that can be used as an input to VaR models. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:441–454, 2003     

Value‐at‐risk for long and short trading positions

In this paper we model Value‐at‐Risk (VaR) for daily asset returns using a collection of parametric univariate and multivariate models of the ARCH class based on the skewed Student distribution. We show that models that rely on a symmetric density distribution for the error term underperform with respect to skewed density models when the left and right tails of the distribution of returns must be modelled. Thus, VaR for traders having both long and short positions is not adequately modelled using usual normal or Student distributions. We suggest using an APARCH model based on the skewed Student distribution (combined with a time‐varying correlation in the multivariate case) to fully take into account the fat left and right tails of the returns distribution. This allows for an adequate modelling of large returns defined on long and short trading positions. The performances of the univariate models are assessed on daily data for three international stock indexes and three US stocks of the Dow Jones index. In a second application, we consider a portfolio of three US stocks and model its long and short VaR using a multivariate skewed Student density. Copyright © 2003 John Wiley & Sons, Ltd.     

Trading activity,realized volatility and jumps

This paper takes a new look at the relation between volume and realized volatility. In contrast to prior studies, we decompose realized volatility into two major components: a continuously varying component and a discontinuous jump component. Our results confirm that the number of trades is the dominant factor shaping the volume–volatility relation, whatever the volatility component considered. However, we also show that the decomposition of realized volatility bears on the volume–volatility relation. Trade variables are positively related to the continuous component only. The well-documented positive volume–volatility relation does not hold for jumps.     

IPOs,trade sales and liquidations: Modelling venture capital exits using survival analysis

This paper examines the dynamics of exit options for US venture capital funds. Using a sample of more than 20,000 investment rounds, we analyze the time to ‘IPO’, ‘trade sale’ and ‘liquidation’ for 6000 VC-backed firms. We model these exit times using competing risks models, which allow for a joint analysis of exit type and exit timing. The hazard rate for IPOs are clearly non-monotonic with respect to time. As time flows, VC-backed firms first exhibit an increased likelihood of exiting to an IPO. However, after having reached a plateau, non-exited investments have fewer possibilities of IPO exits as time increases. This sharply contrasts with trade sale exits, where the hazard rate is less time-varying. We further provide evidence on the impact of economic factors such as syndicate size and composition, geographical location and VC value adding, on exit outcomes.     

The information content of implied volatility in light of the jump/continuous decomposition of realized volatility

In the framework of encompassing regressions, the information content of the jump/continuous components of historical volatility is assessed when implied volatility is included as an additional regressor. The authors' empirical application focuses on daily and intradaily data for the S&P100 and S&P500 indexes, and daily data for the associated VXO and VIX implied volatility indexes. The results show that the total explanatory power of the encompassing regressions barely changes when the jump/continuous components are included, although the weekly and monthly continuous components are usually significant. This evidence supports the view that implied volatility has very high information content, even when extended decompositions of past realized volatility are used. Moreover, adding GARCH‐type volatility forecasts in the regressions confirms these results. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:337–359, 2007     

Short-term market timing using the bond–equity yield ratio

This paper takes a new look at the market-timing ability of the bond–equity yield ratio (BEYR). We compare the short-term profitability of a naive strategy based on the extreme values of the BEYR to the short-term profitability of a sophisticated strategy relying on regime switches. In contrast to previous studies, we do not document any major international evidence that these dynamic strategies deliver significantly higher risk-adjusted returns than the buy-and-hold portfolios. Moreover, the profitability of these active strategies is not improved when the equity yield, instead of the BEYR, is used as a criterion to time the market.