There is always lots of sellers available to sell and push the price down, that is the weak hands. But the important thing is that there is also a lot of buyers who would buy their coins cheap and won't let the price fall down any lower than certain levels.
For example recent weeks showed how there are still a lot of weak hands who panic sell (ie. from $40k+ down to $28k) and also there are a huge number of buyers who would be more than happy to buy bitcoin at a discount (ie. from $28k back to $34k).