competition law. The identification of demand elasticities necessary to conduct a formal definition of product market can be time … product markets suggested by the Competition Commission (the “CC”), we calculate the correlation matrix of residuals and for …

We study empirically how competition among high-frequency traders (HFTs) affects their trading behavior and market …-frequency competition, and contains an exogenous event - a tick size reform - which we use to disentangle the effects of the rising share of … high-frequency trading in the market from the effects of high-frequency competition. We find that when HFTs compete, their …