BraveNewCoin gathers data continuously 24/7 from international exchanges trading a wide range of leading cryptocurrencies. The BraveNewCoin Price Index (BPI) is calculated for each coin. This is the volume-weighted latest average price across all the markets for the coin. It is a nominal rate for a coin in USD dollars that makes currency conversion and comparison of estimated market capitalisations possible.
Exchanges often transact in multiple currencies. Data for each individual coin Market is collected separately by BraveNewCoin. For every data collection cycle the weighted average is calculated for each cryptocurrency market. For example, the Market Weighted Average (MWA) for Bitshares traded in Chinese Yen, BTC-CNY, is the average across all the exchanges trading that currency pair weighted by the volume traded in the last 24 hours at each exchange.
The Marketplace for each coin is the collection of all its markets. The coin's BPI is the volume-weighted average of its MWA's converted to USD.
Check out Bitshares profile page on BNC
http://bravenewcoin.com/bitshares