www.betfair.com
The biggest betting exchange with millions of registered players across the globe and thousands of betting markets.
Online since: 2000-03-15 / Next review: 2018-08-21
Smarkets.com
Very popular online exchange with only 2% of commission on winning bets, but can't measure with Betfair when comparing average betting volume.
Online since: 2005-09-18 / Next review: 2018-12-03