Historical data for this prediction market show that outcome probability remained flat around 20%, since inception. Then, it peaked at 87% just after the bill passed the US Senate.

Source: TradeSports

Post Scriptum: I have copied and pasted the HTML code given by TradeSports (so the chart can be updated in the future), but it does not look good in my browser. Maybe next time, I’ll upload a fixed chart.

Addendum: Paul of SmartCrowd has sent me a corrected code. It’s cute, now. Thanks!… Appreciated. Will make up to you. (I wonder whether TradeSports is aware of its faulty code.)

Addendum 2: Paul confirms my suspicion. Dynamic charts expire once the underlying has expired. It should not be. That’s bad Internet usability. The point of using “permanent links” is to have the content live forever. Many readers will read the archives of this blog (Midas Oracle) in the future. Why depriving them from historical information??

Addendum 3: Paul of SmartCrowd has also told me that NewsFutures charts expire a couple of months after the death of the underlying. Bad usability, again. Here’s why. Now that I know that updated charts will make my blog posts look uninformative for archives diggers, I won’t use this mechanism anymore. I will post normal charts.