Distributions of certain market observables in an on-line betting exchange

Abstract

We analyze high frequency time series of odds and trading volume as extracted from markets on an on-line betting exchange, Betfair.com. As in financial markets, the probability distributions for the change in the market price (odds) are seen to exhibit fat tails. We find significant differences in the statistics of odds changes which occur during the in-play activity of sporting events, when we argue that news is driving market dynamics, and the statistics of odds changes when game-play activity has ceased. Furthermore, we investigate the distribution of the market trading volume as sampled at high frequency and find it can be fit very well to a log-normal distribution function