after I read some articles on the internet, the conclusion that I can find there are several factors that make bitcoin crash one of the many people who sell bitcoin when prices rise but few people who buy, and some FUD scattered. Here are some links I can:
https://www.theguardian.com/technology/2018/feb/02/bitcoin-biggest-bubble-in-history-says-economist-who-predicted-2008-crash
https://www.independent.co.uk/voices/bitcoin-cryptocurrency-price-latest-digital-currency-boom-over-investment-a8199066.html
https://www.express.co.uk/finance/city/914736/Bitcoin-price-latest-what-is-bitcoin-value-will-crash-today-cryptocurrency-news
https://www.marketwatch.com/story/heres-proof-that-this-bitcoin-crash-is-far-from-the-worst-the-cryptocurrency-has-seen-2018-02-09
thanks for the links, already also read this news, the people are now afraid to buy bitcoin because of its instability! https://www.theguardian.com/technology/2018/feb/02/bitcoin-biggest-bubble-in-history-says-economist-who-predicted-2008-crash
https://www.independent.co.uk/voices/bitcoin-cryptocurrency-price-latest-digital-currency-boom-over-investment-a8199066.html
https://www.express.co.uk/finance/city/914736/Bitcoin-price-latest-what-is-bitcoin-value-will-crash-today-cryptocurrency-news
https://www.marketwatch.com/story/heres-proof-that-this-bitcoin-crash-is-far-from-the-worst-the-cryptocurrency-has-seen-2018-02-09