We will see such crashes in bitcoin because bitcoin appreciated so much in so little time so it would be healthy to see some correction. Also, there will be traders would be love to lock in some profits. It's totally normal in crypto universe.
There will always be new investors which have only come into the market and don't have the time to hold the falling coins. Big whales are recognizing the new opportunities and selling other coins they think have reached the high price and they have set the goal for. Everyone has their own standards and limits for selling and this demand for the sold coins is with each month getting ridiculously high.
All the coins that are currently on the market will change their prices in the future. Most recognized ones will change in value to higher limits. Panic is what makes the market stronger because the new opportunities after the panic has started can provide specific coins to get up.
I also forgot to say that the outside factors can also influence the market and because of that some of the whales are trying to control the market and they are actually causing the periodically market crashes over time.