Short for stock and futures trading, meaning seller. The corresponding cow means the buyer.

Short selling is a description of a large number of selling orders in a transaction, and it is called active selling orders.

As for the reason, it is very complicated and it is really impossible to judge on the handicap. Afterwards, you may find "clues".

Generally speaking: when the price is at a relatively high level, it is based on the profit-taking disk to reduce the position; When the price is relatively low, it is necessary for the initial position. (When you have a certain amount of chips in your hand and don't want to add positions, you may sell them first, depressing the stock price, leading to subsequent selling and covering positions on dips. )