Yes, but for selling to crash the price there has to be a lack of demand.

It is the level of demand that determines the price in this situation, not how many coins people are willing to sell.

For you to sell the coin, there must be a buyer. The buyer is expressing at least as much demand for the coin as is equal to the price you are asking.

Should very many people be willing to buy the coin at a higher price, the coins will be resold until they are trading at a price that is near the highest buyers are willing to pay.

For selling to crash the price, we have to imagine that there is very little willingness to pay more for the coins. Demand is what sets the price.