The Determinants of the Time to Efficiency in Options Markets : A Survival Analysis Approach.

This paper examines the determinants of the time it takes for an index options marketto be brought back to efficiency after put-call parity deviations, using intraday transactionsdata from the French CAC 40 index options over the August 2000 – July 2001 period. Weaddress this issue through survival analysis which allows us to characterize how differencesin market conditions influence the expected time before the market reaches the no-arbitragerelationship. We find that maturity, trading volume as well as trade imbalances in call andput options, and volatility are important in understanding why some arbitrage opportunitiesdisappear faster than others. After controlling for differences in the trading environnement,we find a strong and negative relationship between the existence of ETFs on the index andthe time to efficiency.Survival Analysis; Market efficiency; Index Options; Exchange TradedFunds.;

The Determinants of the Time to Efficiency in Options Markets: A Survival Analysis Approach.

This paper examines the determinants of the time it takes for an index options market to be brought back to efficiency after put-call parity deviations, using intraday transactions data from the French CAC 40 index options over the August 2000 - July 2001 period. We address this issue through survival analysis which allows us to characterize how differences in market conditions influence the expected time before the market reaches the no-arbitrage relationship. We find that moneyness, maturity, trading volume as well as trade imbalances in call and put options, and volatility are important in understanding why some arbitrage opportunities disappear faster than others. After controlling for differences in the trading environnement, we find evidence of a negative relationship between the existence of ETFs on the index and the time to efficiency.Survival analysis; Market efficiency; Survival analysis; exchange traded funds; Index options;

Liquidity and Arbitrage in Options Markets: A SurvivalAnalysis Approach

This paper examines the determinants of the time it takes for an index options market to return to no arbitrage values after put-call parity deviations, using intraday transactions data from the French index options market. We employ survival analysis to characterize how limits to arbitrage influence the expected duration of arbitrage deviations. After controlling for conventional limits to arbitrage, we show that liquidity-linked variables are associated with a faster reversion of arbitrage profits. The introduction of an ETF also affects the survival rates of deviations but this impact essentially stems from the reduction in the level of potential arbitrage profits.Limits to arbitrage, liquidity, survival analysis, index options, ETFs

Stock market liquidity and the rights offer paradox.

This paper contributes to the resolution of the rights offer paradox, using a database of French SEOs. We first document higher direct flotation costs, but also improved stock market liquidity after public offerings and standby rights relative to uninsured rights. We find that blockholder renouncements to subscribe to new shares and stock market liquidity are important determinants of flotation method choice. After controlling for endogeneity in the choice of flotation method, we find that public offerings are cost effective and more liquidity improving than standby rights whereas an uninsured rights offering is the best choice for low liquidity, closely held firms. Our results provide new insights as to why firms choose public offerings despite apparently higher costs.bid-ask spread; Security offering; SEO; flotation method; flotation costs; rights issues; public offerings; liquidity;

Stock market liquidity and the rights offer paradox.

This paper contributes to the resolution of the rights offer paradox, using a database of French SEOs. We first document higher direct flotation costs, but also improved stock market liquidity after public offerings and standby rights relative to uninsured rights. We find that blockholder renouncements to subscribe to new shares and stock market liquidity are important determinants of flotation method choice. After controlling for endogeneity in the choice of flotation method, we find that public offerings are cost effective and more liquidity improving than standby rights whereas an uninsured rights offering is the best choice for low liquidity, closely held firms. Our results provide new insights as to why firms choose public offerings despite apparently higher costs.Bid-ask Spread; Public Offerings; Rights Issues; Flotation Costs; Flotation Method; SEO; Security Offering; Liquidity;

Development and improvement of methods for reducing contamination of silicon-kerf from wafer slicing

During wafer slicing, it is shown that carbon contamination can be limited by using organic additive in low concentration. In this way, a reduction of a factor two or three of carbon level in silicon-kerf could be obtained by changing the coolant added to water, with a concentration ten times lower than usual. A second proposed evolution concerns the beam composition, which is usually filled with aluminum-based compounds. New polyester resin beams filled with silicon powder were successfully tested: they did not affect the cutting performance and allows to decrease aluminum concentration in silicon-kerf to a few tens of ppm instead of hundreds. With this evolution of the beams, the main residual contaminant becomes nickel. It was shown that chemical treatment reduced metals in a ratio of three and that after an additional thermal treatment, the carbon level decreased by a factor of six, to reach about zero point two percent. As a conclusion, thanks to cutting liquid and beam composition change, a three-N purity of raw silicon-kerf has been reached at the exit of wafer slicing, without modifying the cutting process. Moreover, additional soft chemical treatment, followed by thermal treatment can reduce carbon concentration and increase silicon-kerf purity to four-N. An improvement of a factor one hundred compared to classical industrial silicon-kerf

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

Genome-wide identification and phenotypic characterization of seizure-associated copy number variations in 741,075 individuals

Copy number variants (CNV) are established risk factors for neurodevelopmental disorders with seizures or epilepsy. With the hypothesis that seizure disorders share genetic risk factors, we pooled CNV data from 10,590 individuals with seizure disorders, 16,109 individuals with clinically validated epilepsy, and 492,324 population controls and identified 25 genome-wide significant loci, 22 of which are novel for seizure disorders, such as deletions at 1p36.33, 1q44, 2p21-p16.3, 3q29, 8p23.3-p23.2, 9p24.3, 10q26.3, 15q11.2, 15q12-q13.1, 16p12.2, 17q21.31, duplications at 2q13, 9q34.3, 16p13.3, 17q12, 19p13.3, 20q13.33, and reciprocal CNVs at 16p11.2, and 22q11.21. Using genetic data from additional 248,751 individuals with 23 neuropsychiatric phenotypes, we explored the pleiotropy of these 25 loci. Finally, in a subset of individuals with epilepsy and detailed clinical data available, we performed phenome-wide association analyses between individual CNVs and clinical annotations categorized through the Human Phenotype Ontology (HPO). For six CNVs, we identified 19 significant associations with specific HPO terms and generated, for all CNVs, phenotype signatures across 17 clinical categories relevant for epileptologists. This is the most comprehensive investigation of CNVs in epilepsy and related seizure disorders, with potential implications for clinical practice