This could very easily be me being confused here, I would expect that if the BANX price was pegged to the USD then the BANX/BTC price graph in coinmarketcap would follow a similar pattern to an inverse of the BTC/USD, I would have expected a price drop of BANX in July, and another drop over the last week for example. I can vaguely see some long-term trend of an inverse of BTC/USD, however generally BANX/BTC is following an upward trend with just two slight dips in the last year maybe its just infrequency of updates or something about the market cap price that I don't understand.
It would be nice if you could briefly explain how it works, if you have the time.
And, sorry for not posting images of the graphs I'm looking at - I didn't work out how to do that yet =)
Yes unfortunately it doesn't update automatically and the calculation is not just the relative price of BTC to USD. The value of USD is in constant fluctuation. Luckily the value of USD has gone up but the value of BTC to USD has remained relatively stable so the minor fluctuations are of little concern. If there is an important change we try to catch it but don't always. This is an area we need to work on and I will see if I can find a way to have it automatically update based on thresholds (otherwise it would never be stable). Basically what it means is that if you bought in when USD was down not to long ago despite the price of BTC to USD being down your overall worth is up.