Wild volatility in Bitcoin today
I'm not surprised that some of the people who had been waiting for $10,000 for a long time are taking some profits.
The scary thing is, something like this can become self-fulfilling. If it starts to spill below $9000, the selling will begin to feed on itself.
The mantra in Bitcoin forever has been to 'hold' (or hodl), but given enough pain, a rush to the exits can be devastating.