There just are not enough sellers left to push the market down in any meaningful way.
There are 15 million BTC. Each of them have own value. When $30k will be to low for them price will move up. But every coin have its price. Some will sell at $40k some at $50k some at $100k. All 15 million BTC have its price. Oh and dont forget that those that will buy at $40k will then again have its own price when will sell. So these 15 million BTC never decrease.
There's a target price on every Bitcoin hodlers or even traders, there's no fix price on the market. Whales knows what to do, and knows when to take profit, while the small time hodlers are just depending on the market situation same thing with the traders. The downtrend is normal scenario of any market, there's a lot of things to be considered, look at the bigger picture, we are still growing in terms of market adoption.
Not sure that whales have a target price. Having watched this market through every peak and trough, I would say many hodlers from the early days that have refused to sell for so many years at what would have seemed immense amounts of money, are not looking at fiat value at all.