Looks like a bug with Atomic Trade. If you click on the price of BTCD at coinmarketcap you will see a list of the exchanges and the price. Atomic Trade is listed with a price of $11 for BTCD while the others are all ~$1.10. That is why the average is so much higher.

Don't know if anybody has mentioned this new exchange somewhere in the thread before but maybe it's a chance for Gridcoin to hit another exchange?
http://www.allcrypt.com/beta/voting.php
Haven't had much experience with exchanging yet but I think it would definitely not harm Gridcoin to spread to one more exchange, especially since the next currency to be added to the exchange is vote-based with the ability to vote every 24h  I think the Gridcoin community has a fair chance of making it (at least from what I've seen so far )