Our Bitfinex Sentiment Index allows you to see what the market currently feels like, bullish or bearish. It is based on market participants sentiment.
BSI as of May 09, 2013 - 04:02:19 PM CDT:
1:1 - Bearish
Bitfinex Irrational Index
This index analyzes user behavior on the market and reflects their coherence and commitment to make profit
Irrational Index for Bear: 85.5
Irrational Index for Bull: 59.4
I am not sure of the exact formula to come up with these numbers but it has been Bullish ever since I have been checking it before the big crash.
My assumption is that the formula has something to do with the amount of longs vs the amount of shorts on the website. So currently there are a lot of people with shorts out on margin.
From my observation, it is usually the most bearish closest to the low. This is the most bearish I have seen.