Why did PIVX crash? Because early adopters got paid. This is as it should be.
The volume on the buy side was 80 BTC 3 days ago, now over 200 BTC.
The volume on the sell side was about 8000 BTC, now the about 6900 BTC.
In between the volume on the sell side dropped to about 7000 BTC and the buying started.
That explains everything.