Surely we are all making estimates about what to do based on our information and knowledge.. .and sometimes based on what others say. 

In my thinking it is pretty unlikely that you are fucked at that $685 buy-in price, unless you sell and lock in your losses  then you would be fucked.  My average buy in price is around that same amount and I am NOT worried (but I only have invested about half that amount, so far, and my investments are diversified.... into other things as well.... so I am prepared to lose all, if things were to go too sour). 

Anyhow, I am buying more BTC if the price goes into the $500s, which may be soon... but I only buy in small increments.. maybe 1 BTC at a time, or less.  if the price goes lower, I will buy more.. but I also have a buy budget... only a certain amount at a time. 

I'm NOT selling or considering selling based on the news that I have NOW in front of me (unless I know for sure the price is going further down by like 10% from my sell, then I may attempt to increase my holdings buy buying back in at the lower price).  At this time, I expect that if I were to sell, then the price would reverse and start to go back up. 

Also, I expect within a week or so, we should be back into the upper 600s... and within a couple of weeks.. maybe stretching out into the 1 month time frame we should be between 750 and 850 area....

Of course, I could be wrong... and that wouldn't be the first time... .. so we each need to go with our gut and our risk profile and our current diversification of investments to make our decisions.