Actually it seems that almost all serious coins are red. Probably people are getting ready for the 1. August SegWit.
There were also too many ICOs build on Ethereum wallet and mostly invested with ETH.
Developers (actually most of them didn't develop anything, just copy paste) got free ETH and now selling all.
I think that is why ETH is the most loosing cryptocurrency at the moment.
What do you think guys?
Yeah its all red
Majority reason i would say is due to The Segwit implementation, because everyone hate changes
For the next point you mentioned, it could be valid because they need real fiat to purchase, hire and other expenses
But i think they don't sell in mass i suppose