An opportunistic algorithm that stays hidden and fires only when it detects liquidity at or better than a limit you set.
A sniper posts nothing and waits. When a large offer appears, or dark liquidity is detected by a small probe, it takes aggressively and then goes quiet again.
It is the right tool for illiquid names where showing any interest moves the price, and the wrong tool when you must finish by a deadline, because it makes no promise to complete.
Example: you want 150,000 shares of a stock that trades 200,000 a day, limit 12.50. For two hours nothing happens. A seller then posts 90,000 at 12.48 and the sniper takes all of it in milliseconds. A vwap-algo would have paid up in dribs and drabs all morning.
Original diagrams for the ideas on this page. Illustrative, not real market data.
The bid-ask spread. Buy orders sit below, sell orders above, and the gap between the best bid (50.01) and best ask (50.04) is the spread you pay to cross. Bar length shows the size resting at each price.
Educational only, not advice. Spotted an error? Post in Site Feedback.