Liquidation
Forced closing of a leveraged position when collateral runs out.
A liquidation is a position closed by the exchange when losses consume the collateral. For the market this is not an ordinary trade but a forced one: it must be closed at any price, so a cascade of liquidations accelerates the move by itself. Hence the characteristic sharp candles with long wicks — price reaches a dense cluster of stops and leveraged positions, takes them out and returns. Liquidation maps show where those clusters sit.