I wasn't sure either and did my first 10% buy in at $ 8500. Then doubts came into place and I left the $ 8000 level for what it is. My gamble now is 20% on $ 7800 | 30% on $ 7400 and 40% at $ 6800.
Since this 100% is still not 100% of my money I can still make use of some more when it hits 4 or 2000? Who knows?
p.s. Of course final decisions are made while they are there. If they will even get there.