I’ve been saying for a while now that prediction markets are going to play a huge role in everyday social media. We aren’t there yet but things are starting to pick up.

“Prediction markets (also known as predictive markets, information markets, decision markets, idea futures, event derivatives, or virtual markets) are speculative markets created for the purpose of making predictions. Assets are created whose final cash value is tied to a particular event (e.g., will the next Prime Minister be a Liberal) or parameter (e.g., total sales next quarter). The current market prices can then be interpreted as predictions of the probability of the event or the expected value of the parameter. Prediction markets are thus structured as betting exchanges, without any risk for the bookmaker.

People who buy low and sell high are rewarded for improving the market prediction, while those who buy high and sell low are punished for degrading the market prediction. Evidence so far suggests that prediction markets are at least as accurate as other institutions predicting the same events with a similar pool of participants.” (courtesy of Wikipedia)

So we wanted to try it out. Signing with a Chicago-based company, Inkling Markets, we created a test project called Whosthekiller.com, predicting what will happen on the CBS’s TV show Harper’s Island.

Harper’s Island is horror thriller/mystery mini series. The show will have only one season comprising 13 episodes. One or more characters will be killed off each week. To make things even better, the series had been shot in Vancouver and the actors and actresses were not told about their deaths until the day that each script was given. You can watch all the episodes for free on Globaltv.ca.

Our site, Whosthekiller.com, is a prediction market around the hit show. New users start with a virtual pot of $5000 to buy shares in whichever outcome they think is most likely in a given market.

Right now the current markets that you can trade on are:

Who is the killer?

Who will die in episode eight?

Is John Wakefield still alive?

Will Henry and Trish still get married?

Will CBS cancel Harper’s Island before all 13 episodes have aired?

In which episode will the identity of the killer(s) be revealed?


Here is the best part…

we are often right.

Episodes 4 and 5 (with 75 and 90 traders respectively) we correctly predicted who would die each night. For episodes 6 and 7  we were damn close with the individuals who died being the 2nd choice.

Can we get it right for episode 8? We think so.

Invite your friends to sign up, add them to your network under the “Friends” tab to see each others stats, and start competing today. Track your friends’ progress and compete to see who’s got the best guess.

Happy trading folks,

Adam M.


I should have mentioned this is a free service.