Correlations between U.S. stocks and the aggregate U.S. market are much greater for downside moves, especially for extreme downside moves, than for upside moves. We develop a new statistic for measuring, comparing, and testing asymmetries in conditional correlations. Conditional on the downside, correlations in the data differ from the conditional correlations implied by a normal distribution b...

We analyze the effects of differences of opinion on the dynamics of trading volume in stocks and options.We find that disagreements about the mean of the currentand next-period public information lead to trading in stocks in the current period but have no effect on options trading. Without options, we find that disagreements about the precision of all past and current public information affect ...

Thirty-six Trypanosomatidae stocks isolated from various hosts and geographical areas in Colombia and 7 others from Bolivia, Chile, Honduras and Panama have been surveyed by Multilocus Enzyme Electrophoresis (MLEE). Part of the Colombian stocks were previously characterized by morphology and biological behavior as belonging to Trypanosoma cruzi and Trypanosoma rangeli taxa, others were unknown ...

Randomly amplified polymorphic DNA (RAPD) has emerged as an effective genetic marker for analysis of Trypanosoma cruzi population variability. This method has been used to study the genetic variability of Mexican T. cruzi stocks and to relate these results to previous classifications. High clonal diversity was observed among the Mexican populations: 24 RAPD types were scored among 56 stocks ana...

When utility is nonseparable in nondurable and durable consumption and the elasticity of substitution between the two consumption goods is sufficiently high, marginal utility rises when durable consumption falls. The model explains both the crosssectional variation in expected stock returns and the time variation in the equity premium. Small stocks and value stocks deliver relatively low return...

Climatic conditions shift gradually over millennia, altering the rates at which carbon (C) is fixed from the atmosphere and stored in the soil. However, legacy impacts of past climates on current soil C stocks are poorly understood. We used data from more than 5000 terrestrial sites from three global and regional data sets to identify the relative importance of current and past (Last Glacial Ma...

Crayfish stocks collapsed in Turkey in mid 1980’s due to crayfish plague epidemics, with up to 25% survival in some cases. The collapsed stocks have then recovered slowly and commercial crayfish fishery was reinitiated gradually within a decade. We examined the prevalence of Aphanomyces astaciDNA in the narrow clawed crayfish (Astacus leptodactylus) collected from two Turkish lakes, Lake İznik ...

This work discusses most frequently traded stocks of National stock exchange of India. A prediction based portfolio optimization model is considered to present an ideal portfolio out of the considered stocks. Neural network has been used to predict stock returns and a risk measure is derived that has the same foundation as that of mean variance model. The architecture of the network is designed...

In this paper a data mining approach for classification of stocks into clusters is presented. After classification, the stocks could be selected from these groups for building a portfolio. It meets the criterion of minimizing the risk by diversification of a portfolio. The clustering approach categorizes stocks on certain investment criteria. We have used stock returns at different times along ...

Stocks with better past returns crash more than other stocks on May 6, 2010. I find evidence that this is related to such stocks being unattractive to contrarian buyers. This suggests the importance of contrarian investors in stabilizing price fluctuations. However, the glass is half full---that the contrarian investors shun certain types of stocks limits the extent of price stability that reli...