Zero Rate
Also called: spot rate, zero coupon rate, zero curve
A zero rate is the yield on a single cash flow at one maturity, with no coupons in between — the pure price of time for that date. Zero rates are the building blocks of valuation because every instrument is a bundle of dated cash flows, each discounted at its own zero rate. A coupon bond's yield to maturity is a messy average of them, which is why curves are built in zero space rather than yield space.
Where this is taught
Definitions are the trailer. These free levels turn Zero Rate into something you play — one bite-size lesson, with worked examples, a quiz and XP.