The Greeks
The sensitivities of an option's price, each named after a Greek letter: delta (to the underlying's price), gamma (to delta itself), vega (to volatility), theta (to time passing) and rho (to rates). They're the dials a trader watches to hedge a book.
Where this is taught
Definitions are the trailer. These free levels turn The Greeks into something you play — one bite-size lesson, with worked examples, a quiz and XP.