There was a lot of instability in the market after Mike Hearn came out in an extremely public manner against bitcoin's current direction under leadership of the Core development team.
Central to the criticism of Core is how many of the developers are associated with the for-profit company Blockchain. This creates a perception of a conflict of interest, in that the devs are more likely to pursue courses of action that would benefit their employer's services.
Bitcoin Classic has recently been gaining some steam with 15% of nodes currently running bitcoin being Classic:
For now the market has shown some signs of volatility in the face of news related to the ongoing debate, so watch this story closely.