A lay bet at 3.0 against a $40 backer stake puts $80 on the line, not $40. Exchange arbitrage depends on understanding that gap. You will learn how lay liability works, how to size a back and lay pair so both outcomes pay the same before commission, and why a thin gap can shrink fast once a 5 percent fee on winnings enters the picture. A worked example backs Team A at 2.50 and lays at 2.40. You will also check that the two contracts match on timing, resolution and postponement rules, and consider what happens when only part of your order is filled and one leg sits unmatched.
Learning objectives
- Reproduce the mathematical or scenario analysis.
- Explain contract, execution, and settlement assumptions.
- Identify when the apparent opportunity is not reliably actionable.
