From my opinion this is possible only when the every person on the earth stops using/investing in the bitcoin.Which is nearly impossible , because as there are believers that bitcoin is ponzi scam , there are some hardcore believers of bitcoin. So I think in our lifetime we wont see bitcoin stopping or maybe some other currency like ethereum would replace it.

I second that and it's actually happening.

These are people who own large quantities of BitCoins. As a result they can raise or lower the BTCUSD rate on any exchange more-or-less at will. This power can be used to affect the market volatility to their advantage. There is little doubt that at least a few of the Whales are benefitting from BitCoin’s volatility by making use of their power to change the exchange rate.