Trades in DAX index options with identical maturities cluster around particular classes of strike prices. For example, options with strikes ending on 50 are less traded than options with strikes ending on 00. Clustering is higher when options with close strike prices are good substitutes. The...

More liquid financial contracts are claimed to draw trading volume from contracts for which they are close substitutes. We provide the first analysis of how trading volume across existing financial contracts is affected by changes in the factors that govern the degree to which they are...