EQpractitionerconcept
Implied Volatility
The volatility input that makes a model reproduce a market option price.
01Intuition
Build the mental model first.
Implied volatility is a quote coordinate, not a forecast delivered by the market.
ONE-LINE DEFINITION
The volatility input that makes a model reproduce a market option price.
02Mathematics
Now make it exact.
Notation and units
Decimal rates and volatilities, year-fraction time and continuous compounding unless stated otherwise.
03Assumptions
Every model has a price.
01
Educational conventions are stated explicitly and may simplify market quotation or settlement details.
02
Rates are continuously compounded unless the section says otherwise.
03
Inputs are deterministic in the base model.
“An unstated convention is a future reconciliation break.”— THEQUANTBATEMAN
04Market use
Why a quant cares.
Normalises option prices across strikes, maturities and underlyings.
Intuition→Mathematics→Implementation→Desk risk
05Desk view
FRONT OFFICE VIEW
The hedge has opinions.
Start with the quote convention, then ask which EQ risk survives the hedge. A number without its convention is merely well-dressed ambiguity.
Ask Bateman about this model →06Related