A scanner flags a gap between two prices, and it looks like an easy win. Then you notice one of those prices is eight seconds old. Arbitrage quote freshness is the check that separates a real opening from a timing mismatch. This expert lesson walks through a read-only pipeline that moves a candidate from detected to validated to audited, with clear reasons to reject along the way: missing timestamps, unknown void rules, a suspended market. You define quote age, see why a fast feed can still carry a stale source price, and replay bad cases like a second leg that reprices by one tick. The payoff is simple. You trust a hit only when you can show your work.
Learning objectives
- Reproduce the mathematical or scenario analysis.
- Explain contract, execution, and settlement assumptions.
- Identify when the apparent opportunity is not reliably actionable.
