There is no reason for this down turn I think very powerful and rich people are playing with crypto currencies which might not be quite as independent and interference free as people seem to think they are. Why should all of these coins prices fluctuate according to bitcoins performance? I think something like ethereum has no reason to be influenced by Bitcoin, aren't these types of coins decentralized? So I really think other things are at work here.
In any case I think everyone should hold their Steem and see what happens after August 3.