Gunning refers to the practice of large traders or institutions deliberately pushing prices toward levels where stop-loss orders are clustered. Once the stops are triggered, the resulting flood of orders moves the price further, allowing the gunners to profit from the liquidity.
Example
“Institutional traders noticed a large cluster of stop-loss orders below the $50 support level and aggressively sold to trigger those stops, causing the price to briefly crash to $48 before rebounding.”