Just for a laugh, decided to run the numbers.

Taken from Banx.io trade history, this is all the trading for the last 24 hours:

                        Banx Price   Quantity             BTC cost

83417   Buy   0.00671000   69.00000000   0.46299000   Jun 18, 2015 7:02 PM
83413   Buy   0.00671000   55.00000000   0.36905000   Jun 18, 2015 5:32 PM
83408   Buy   0.00671000   145.00000000   0.97295000   Jun 18, 2015 4:00 PM
83406   Buy   0.00671000   90.00000000   0.60390000   Jun 18, 2015 2:32 PM
83405   Buy   0.00671000   128.00000000   0.85888000   Jun 18, 2015 1:01 PM
83403   Buy   0.00671000   129.00000000   0.86559000   Jun 18, 2015 11:49 AM
83400   Buy   0.00671000   136.00000000   0.91256000   Jun 18, 2015 10:29 AM
83398   Buy   0.00671000   127.00000000   0.85217000   Jun 18, 2015 9:03 AM
83397   Buy   0.00671000   149.00000000   0.99979000   Jun 18, 2015 7:58 AM
83396   Buy   0.00671000   96.00000000   0.64416000   Jun 18, 2015 6:57 AM
83395   Buy   0.00671000   97.00000000   0.65087000   Jun 18, 2015 5:51 AM
83394   Buy   0.00671000   57.00000000   0.38247000   Jun 18, 2015 4:30 AM
83393   Buy   0.00671000   58.00000000   0.38918000   Jun 18, 2015 3:26 AM
83392   Buy   0.00671000   144.00000000   0.96624000   Jun 18, 2015 1:58 AM
83391   Buy   0.00671000   135.00000000   0.90585000   Jun 18, 2015 12:25 AM
83390   Buy   0.00671000   93.00000000   0.62403000   Jun 17, 2015 11:21 PM
83388   Buy   0.00671000   62.00000000   0.41602000   Jun 17, 2015 10:19 PM
83387   Buy   0.00671000   74.00000000   0.49654000   Jun 17, 2015 9:01 PM
83385   Buy   0.00671000   1.40000000           0.00939400   Jun 17, 2015 8:45 PM
83382   Buy   0.00671000   72.00000000   0.48312000   Jun 17, 2015 7:29 PM


Being too lazy to get the calculator out, I estimate total BANX trading on Banx.io at around 13 BTC / $3250 over the last 24 hours.
CMC shows 62 BTC / $15,500:
http://coinmarketcap.com/currencies/banxshares/#markets

Er....anyone got a sane explanation ?