ratio of sold and bought coins?
so some people are buying or selling coins from no one?
every bought coin has a seller
and every sold coin has a buyer
how are these numbers derived?
forgive me if this was already addresses
My bet is that:
sold coins = sold into bid walls
bought coins = bought from ask walls.
so orders that are over a limit of a certain arbitrary amount?
like 50 orders of 2BTC don't make the scale but 1 order of 100BTC does
Take the 'walls bit out of what lucas.sev said and you got it ...
All trades are considered.
When a bid is hit a coin is considered 'sold'
When an ask is taken a coin is considered 'bought'
So it is a measure of whether the current price action is more biased towards price being knocked down by sellers (bearish), or raised by buyers (bullish)
There is always a spread between bid and offer ... the one who crosses it is considered the indicator of sentiment in this model
Like this a big dump, where asks are continuously being hit and price knocked down, the needle would swing to 'bearish' very rapidly.
As I understand it, how far the needle swings is a function of the ratio of coins bought to coins sold over the period being looked at. Not sure on the calibration though.
Hope this helps