A wick is a slang expression used by traders to denote a sharp drop in a cryptocurrency's price over a very short period of time, most often within a five- or fifteen-minute interval. On the chart, such a move looks like a long vertical candle or a sharp dip, after which the price frequently returns to its previous levels just as quickly.
Such moves arise for various reasons: a cascading liquidation of leveraged positions, the triggering of stop orders, a large market sell order, or a temporary drop in order book liquidity. When there are few buy orders nearby, even a relatively small volume of selling can sharply push the price down.
For a trader, understanding the nature of such spikes is important from a risk management standpoint. Sharp dips can knock out stop-losses and provoke emotional decisions, so experienced market participants build the possibility of heightened volatility into their strategy in advance and do not perceive every such move as a change in the overall trend.
