Bitcoin has always been operating in 4 year cycles where it crashes at the end
2014, 2018, 2022, 2026
It's actually great because every 4th year people really get super sad and give up on it (or well that's how it feels like)
There's also surely some sentiment pumping to push the price down so people can buy in cheap again
The next cycle up is 2027-2031
(And it has something to with the halvening which happens every 4 years cutting the reward for miners in half)