It is now about 6 days since Ethereum fell from around $350 to bounce down to as low as $.10 and settle now at $220.  But that doesn't really matter to users of Poloniex and other exchanges because the exchanges are not allowing withdrawals or deposits of ether.  The value is therefore being set by a small subset of owners of ether who are trading on  fewer exchanges.   In effect, the market is skewed. 

The only thing that changed about the Ethereum platform itself is that the Ethereum development community was unable to code temporary workarounds before implementing sharding and proof of stake in order to keep pace with the explosion of initial coin offerings of the last few weeks.  The gap between implementation of sharding and proof of stake and an escalating number of potential users of the platform has hit us hard and damaged our credibility.  

It is kind of wonderful, though!  Too many development teams (ICO offerers) seeing potential and actually putting effort into their visions!  I like that.  Even though it is a big OUTCH for the short term.