The illegal shadow of real strategies: faking liquidity or news to move the price. Covered here for recognition and detection only, never as an operational how-to.
Large orders entered with no intention to execute, to move the price before cancelling. The deception is the crime.
What to notice. Manipulation isn't a category, it's a continuum – and the line the law actually draws (gold) sits not where trading gets aggressive but where it gets deceptive. Latency arb and icebergs are sharp yet bona fide; spoofing and pump-and-dump fail because the intent is to mislead. Drag the line and watch the same practices reclassify – exactly the judgement a regulator makes.