Open Prediction Markets

Drupal user Rob Knight has begun work on a new module - http://drupal.org/project/pm - which aims to provide a market maker in Drupal.

A quick review of his TODO.txt shows a bit of work left (userpoints integration, in particular, is important).

The "gaming" of anything is generally bad. In the case of prediction markets, there are occasionally some which easily be gamed by a broad audience. There is a new market on hubdub for:

How many results will a Google search for 'Switchy McSwitchenstein' yield by the end of April 2008?

Happy Path Trading

The "happy path" is done (has been for a while actually). You can buy/sell portfolios of contracts. You can buy/sell individual contracts as long as the number you want to buy/sell matches perfectly with someone else. This is pretty exciting to me. I've even got some validation at order entry and trade execution to make sure things "good."

Some Oddball Paths

Partial match (and vice versa):
1. Order placed for 100 items
2. Match placed for 50 items
3. Match satisfies the first 50 and is executed/closed

There were recently two launches of prediction markets that are worth writing about: HubDub and The Industry Standard.

Prediction Market with News Aggregator