A price that looks wrong on your screen is not always a price you can take. Stale lines are the classic example. This lesson follows a timestamped case where a reference quote jumps from -110 to -135 while a slower venue still shows the old number. It explains why that gap may be a suspended market, a delayed feed or a different contract rather than a free edge. You learn the three times that matter: when news broke, when the provider saw the price, and when you tried to act. It closes with a step-by-step investigation and a stress test for latency, so you can tell a real opportunity from a screenshot of one.
Learning objectives
- Reproduce the lesson calculations.
- Identify the assumptions and conditions that can invalidate the modeled edge.
- Design an auditable research or practice workflow.
