The concentration of many stop orders around the same obvious structural area, creating a pool of aggression that can be released when the triggers are reached.
Full Explanation
Traders are often taught similar stop-placement rules: below the swing low, above the swing high, outside the range, or beyond an obvious level. When many people identify the same structure, their stops naturally collect in similar areas. No coordination or conspiracy is required.
Those orders remain dormant until their trigger prices are reached. Then they convert into market orders together. Stops below lows become aggressive selling; stops above highs become aggressive buying. A cluster can therefore release a sudden wave of aggression into the market.
What happens after the stops trigger is not predetermined. Deep opposing liquidity can absorb the wave and price may reverse. Thin liquidity can allow the triggered aggression to relocate price farther. This mechanical chain is more useful than saying the market 'hunted' the stops, because it explains both the trigger and the possible outcomes without assigning intent to price.