Its probably miners, mostly Idcray maybe?!

They still have more than half the network hash. Figure with 86400 seconds in a day, and figure blocks at around 200 seconds each roughly, would put around 31000 coins a day from mining. Idcray gets probably around 15-20k coins a day from their mining hashpower. Thats around 5-7btc everyday they dump on top of anyone else mining that dumps ( another 5-6btc ), and any other portion of their stash that Idcray wants to dump. With low volume days around 20-30btc it will keep price down abit.