Giant ponzis do not run for more than 10 years. At $600,000,000,000 invested in Bitcoin the money supply has dried up. Bitcoin has crashed from $20,000 to $12,000
and high profile people calling Bitcoin a giant scam there is ever increasing risk of international police raiding Bitcoin mines
Bitcoins will not go down to $400 dollars, the price in the market might go dip today but still it will manage to grow again due to traders who will take advantage of the cheap price today.
There is no chance for BTC to drop to 400$, iit's just not possible. The market correction is in progress and thing should get back to normal in few weeks. Many analysts expect BTC to go up to 8-10k by the end of the year.