A collective market sell-off that occurs when large quantities of a particular cryptocurrency are sold in a short period of time.
A dumping may occur when the market is spooked by outside factors such as economic turmoil in global markets, or even as a response to a particular news story.
More notably, a dumping is likely when a cryptocurrency’s price repeatedly meets a point of resistance. Take May 2018, for example, when Bitcoin was in a robust period of upward movement to push it above the significant figure of $10,000. Again and again it bounced around the $10,100 mark, eventually nudging $10,200 where it hit a hard ceiling of rejection.
It is likely those whales then re-entered the market to buy up more Bitcoin at a massively deflated price, resulting in huge profits.