As you might know already, Chinese and French banks are no longer supporting any transactions that involve bitcoins. Therefore, all chinese traders are doing a massive BTC dump.

I just sold all my BTC (made a loss but with this crash, its better to get out sooner than later)

Sources:

http://www.smh.com.au/business/markets/currencies/china-bans-banks-from-bitcoin-transactions-20131206-2yugy.html
http://articles.economictimes.indiatimes.com/2013-12-05/news/44808398_1_pseudonym-satoshi-nakamoto-bitcoin-trading-platform-chinese-banks
http://business.time.com/2013/12/05/bitcoin-plummets-after-china-bans-it-from-banks/
http://www.bbc.co.uk/news/technology-25233224
http://www.reuters.com/article/2013/12/05/china-bitcoin-idUSL4N0JK1KZ20131205
http://www.aljazeera.com/news/asia-pacific/2013/12/bitcoin-value-dives-after-china-banks-ban-2013125141919464366.html