Understanding the ex-ante cost of liquidity in the limit order book: a note.

El presente trabajo estima una nueva medida de coste de liquidez de los activos financieros en un mercado dirigido por órdenes. Esta medida, denominada función de liquidez, recoge el coste ex-ante de comprar y vender simultáneamente una determinada cantidad de acciones haciendo uso de toda la información ofrecida por el libro de órdenes. De esta manera se superan las dificultades que la consideración por separado de la horquilla de precios o la profundidad ocasiona sobre la caracterización de la liquidez de los diferentes activos.This paper estimates a new measure of liquidity costs in a market driven by orders. It represents the cost of simultaneously buying and selling a given amount of shares, and it is given by a single measure of ex-ante liquidity that aggregates all available information in the limit order book for a given number of shares. The cost of liquidity is an increasing function relating bid-ask spreads with the amounts available for trading. This measure completely characterizes the cost of liquidity of any given asset. It does not suffer from the usual ambiguities related to either the bid-ask spread or depth when they are considered separately. On the contrary, with a single measure, we are able to capture all dimensions of liquidity costs on ex-ante basis.Función de liquidez; Coste de liquidez; Libro de órdenes límite; Horquilla de precios; Profundidad; liquidity function; liquidity cost; open limit order book; bid-ask spread; depth;

Information Transmission around Block Trades on the Spanish Stock Market.

This study investigates the informational effects of large transactions, or Block Trades (BT), in the Spanish Stock Exchange (SSE). In the open market period, this topic was not facilitated in the SSE as it was in other markets until 1998. The SSE thus provides a special environment for analysing the information transmission of these specific transactions. It is assumed that information can be better reflected by changes in true asset value, proxied by the midpoint of bid-ask best quotes. Therefore, we will look at changing true asset value orders instead of trades. Three different effects are studied around BTs: price, liquidity and information transmission. To capture them, three different endogenous variables are considered: true asset returns, relative spreads and adverse selection spread component. With this approach, no clear effects of BTs are found. The main result of the study is that there seems to be an increase in information asymmetries when one looks at the adverse selection spread component in some of the different subsample classifications (buyer, seller and sweeping BT), but there is no significant permanent effect on returns. This result could be related to insiders trading in the market. In sharp contrast with adverse selection evidence, a temporary decrease in bid/ask spread around BTs is also observed. These changes reflect temporary liquidity effects related to other spread components (order processing costs and inventory costs).

Information transmission around block trades on the Spanish stock market

Current fmancial research is placing increasing attention on the effects of large transactions, or Block Trades (BT), on the fmancial markets. In order to analyze whether BT transmit information, we assume that information can be better reflected by changes in asset true value, proxied by the midpoint of bid-ask best quotes, instead of transactions prices or returns. Moreover, following market microstructure literature, we also look at changes in relative spread and in their adverse selection component. The Madrid Stock Exchange offers us a particularly appropriate testing ground for examining these issues, since this topic has not been facilitated as in other markets till 1998. We analyze 195 BT, classified according with trading volume, the side of the market initiating the BT (buyer, seller or indeterminate initiated), its type (inside the spread, sweeping or not classified) and if they change or not the asset true value. The main result of the paper is that it seems that there is BT information transmission when we look at adverse selection spread component in the different subsample classification, but there is no significant permanent effect in returns. We also observe changes in liquidity around BTs but the effect is related with temporary spread component

Asset pricing and systematic liquidity risk: An empirical investigation of the Spanish stock market.

Systematic liquidity shocks should affect the optimal behavior of agents in financial markets. Indeed, fluctuations in various measures of liquidity are significantly correlated across common stocks. Accordingly, this paper empirically analyzes whether Spanish average returns vary cross sectionally with betas estimated relative to three competing liquidity risk factors. The first one, proposed by Pastor and Stambaugh (2003), is associated with the temporary price fluctuation reversals induced by the order flow. Our market-wide liquidity factor is defined as the difference between returns highly sensitive to changes in the relative bid–ask spread and returns with low sensitivities to those changes. Finally, the aggregate ratio of absolute stock returns to euro volume, as suggested by Amihud [J. Financ. Mark. 5 (2002) 31], is also employed. Our empirical results show that systematic liquidity risk is significantly priced in the Spanish stock market exclusively when betas are measured relative to the illiquidity risk factor based on the price response to one euro of trading volume on either unconditional or conditional versions of liquidity-based asset pricing models.Systematic liquidity risk; Expected returns; Bid–ask spread; Order flow; Trading volume;

Understanding the ex-ante cost of liquidity in the limit order book: A note

This paper estimates a new measure of liquidity costs in a market driven by orders. It represents thecost of simultaneously buying and selling a given amount of shares, and it is given by a single measure of ex-ante liquidity that aggregates all available information in the limit order book for a given number of shares. The cost of liquidity is an increasing function relating bid-ask spreads with the amounts available for trading. This measure completely characterizes the cost of liquidity of any given asset. It does not suffer from the usual ambiguities related to either the bid-ask spread or depth when they are considered separately. On the contrary, with a single measure, we are able to capture all dimensions of liquidity costs on ex-ante basis.liquidity cost, liquidity function, open limit order book, depth, bid ask spread

ASSET PRICING AND SYSTEMATIC LIQUIDITY RISK: AN EMPIRICAL INVESTIGATION OF THE SPANISH STOCK MARKET

It seems reasonable to expect systematic liquidity shocks to affect the optimal behavior of agents in financial markets. Indeed, fluctuations in various measures of liquidity are significantly correlated across common stocks(Chordia, Roll and Subrahmanyam (2000)). Thus, this paper empirically analyzes whether Spanish expected returns during the nineties are associated cross-sectionally to betas estimated relative to two competing liquidity risk factors. On one hand, we propose a new market-wide liquidity factor which is defined as the difference between returns of stocks highly sensitive to changes in the relative bid-ask spread less returns from stocks with low sensitivities to those changes. We argue that stocks with positive covariability between returns and this factor are assets whose returns tend to go down when aggregate liquidity is low, and hence do not hedge a potential liquidity crisis. Consequently, investors will require a premium to hold these assets. Similarly, note that in the case of assets that covary negatively with the liquidity factor, investors may be willing to pay a premium rather than to require an additional compensation. On the other hand, Pastor and Stambaugh (2002) suggest that a reasonable liquidity risk factor should be associated with the strength of volume-related return reversals since order flow induces greater return reversals when liquidity is lower. Our empirical results show that neither of these proxies for systematic liquidity risk carries a premium in the Spanish stock market.

In situ decolorization monitoring of textile dyes for an optimized UV-LED/TiO2 reactor

Heterogeneous photocatalysis, using photocatalysts in suspension to eliminate diverse contaminants, including textile wastewater, has several advantages. Nevertheless, current absorbance and decolorization measurements imply sample acquisition by extraction at a fixed rate with consequent photocatalyst removal. This study presents online monitoring for the decolorization of six azo dyes, Orange PX-2R (OP2), Remazol Black B133 (RB), Procion Crimson H-EXL (PC), Procion Navy H-EXL (PN), Procion Blue H-EXL (PB), and Procion Yellow H-EXL (PY), analyzing the spectrum measured in situ by using the light scattering provided by the photocatalyst in suspension. The results obtained have corroborated the feasibility of obtaining absorbance and decolorization measurements, avoiding disturbances in the process due to a decrease in the volume in the reactor.Peer ReviewedPostprint (published version