The term Sell Wall pertains to the huge limit sell order or an accumulation of sell orders through one price level.
The direct opposite of a buy wall, a Sell Wall may be created by one entity. It can also be developed through the sum of orders placed within the same price level. The single entity responsible for the creation of the Sell Wall is referred to as a “whale”, a crypto trader that holds a great deal of crypto coins enough to change the behaviour of the crypto market. (See “WHALE”)
The Sell Wall may be used by crypto traders to develop a certain impression in the market. This then prevents a cryptocurrency from exceeding that value given that supply is always inclined to outstrip demand once an order is launched.