Or just whales trying to manipulate the price and put pressure on it to go below the 4 digit price. They are successful, however the price did recovery very quick, meaning that people, just casual joe's also buying at every price drop.
However, I still remember way back, early 2018, when the price started to go down very fast. A lot of people are saying that the price won't go down to 4 digit. This was the time when we just reach an all time high of almost 20k, but we all know that after that the price did go down as low as $3200. So there is no safe upper or lower bound here, it is still base on the demand at any given time.
you can't really compare the big bitcoin bubble of 2017 (@ $20k price) with the current price level. where we are now is just after a recovery from a massive drop down to $3k not a rise and far from being anywhere near a bubble! as a result you can't expect a drop, specially of the same size here...
but you are correct, the price could drop back to 4 digits. i wouldn't expect it to last there for long though. as we have seen people are too eager to buy it and the market's overall sentiment is bullish even if they are temporarily doubtful.