http://coinmarketcap.com/currencies/views/filter-non-mineable-and-premined/
Crap site? That's pretty harsh isn't it? Coinmarketcap just takes the averages from all the exchanges DRK is listed on. The price it lists is in line with the price on Cryptsy which has the largest volume of trades. If you look at that chart that was posted you'll see that the 17.4% increase is for 30 days. Coinmarketcap uses 24hrs. If you look at the thirty day chart for DRK at coinmarketcap you can see that increase. Instead of calling coinmarketcap a crap site maybe you should make sure that it's showing the same data as the other site. In this case it isn't.
If you go to the currencies tab at coinmarketcap and select "all currencies" it will show the last 7 days change percent.
Maybe you should send a request to coinmarketcap to include a 30 day change percent instead of attacking them because the way they display data doesn't show the 30 day change percent. I'm sure it would be easy for them to implement and it's something I would like to see as well.
I did check. It was incorrect over 24 hours. I also checked its last update timestamp just to make sure it wasn't just missing this morning's minipump. The 24 hour data was not even close when I made that post and probably isn't now.
Isn't their 24 hours literally a rolling 24 hour period?
Yes it is.
Edit:
I stated in a previous post that I didn't know how they averaged. Upon further inspection I determined that they use a 24 hour rolling period.