Fundamental Theorem of Asset Pricing
Also called: fundamental theorem of asset pricing
The result tying it all together: no arbitrage exists if and only if there's a risk-neutral probability measure that prices everything. It's why the risk-neutral trick is valid, not just convenient.
Where this is taught
Definitions are the trailer. These free levels turn Fundamental Theorem of Asset Pricing into something you play — one bite-size lesson, with worked examples, a quiz and XP.