Ether's Genesis block sale ends Tue Sep 2.
There are probably people selling BitsharesX, at a significant profit, and moving it into there, hopping to repeat.
And, at least some people are moving Bitshares into the newly available BitUSD, hoping to be able to move the equity back, once it Bottoms.
So my assumption is that things are just re-adjusting, accordingly, getting ready for the next move up as more equity continues to come in. Things take time, and they never go straight up.