Image via WikipediaAt Hubdub we like to compare or forecasts with prices from a wide range of prediction markets, bookmakers and betting exchanges. One challenge we have is that only a small subset of the 2,000 markets we have traded are also traded on other exchanges. The exchanges we tend to consult are:

Prediction markets: Intrade, NewsFutures, Inkling and Iowa Electronic Markets

UK bookmakers: Oddschecker

Betting exchanges: Betfair and BETDAQ

One market that is traded on all the exchanges is the future US president market. In general the prices in this market are fairly consistent between all the exchanges, with candidates forecasts generally within 3% of each other. However in the past 10 days we’ve noticed that while Barack Obama’s price surged with us and nearly all the other exchanges, it appeared to stick in the low 50’s with Intrade.

Between Intrade and Betfair (both real money markets) there existed a 10% difference in price which lasted for several days. This is highly unusual as normally traders arbitrage between markets bringing prices back in line. Yesterday, FiveThirtyEight published research to suggest that the Intrade markets were in fact being manipulated. As of this moment Intrade has a price of 57% for Obama compared with ~64% on Betfair (and most of the other exchanges).

Popularity: 7% [?]