It looks like the coinmarketcap markets page for XMR is getting XMR/BC data from Bittrex right now, instead of XMR/BTC, which is messing up the average price, putting XMR at #2 on the main page ranking: http://coinmarketcap.com/currencies/monero/#markets

The XMR/BC data on Bittrex isn't even right (has a massive spike): https://bittrex.com/Market/Index?MarketName=BC-XMR

Edit: Looks to be fixed already.

Edit 2: The 7 day chart will need to be fixed (http://coinmarketcap.com/currencies/monero/). The one hour percent change is also wrong but will correct itself.