Lecture 6 Flashcards
What is implied volatility in the context of the Black-Scholes (BS) model?
It is the volatility value that, when input into the BS formula, makes the calculated option price equal to the observed market price.
How is implied volatility different from historical volatility?
Implied volatility reflects the market’s expectations for future price fluctuations, while historical volatility measures past price movements.
What does implied volatility allow traders to compare across different options?
It allows traders to compare how expensive options are in a standardized way.
What is the main input to the BS model that is “backed out” using implied volatility?
Volatility (Sigma)
Does using implied volatility require the BS model to be accurate?
No, the BS model is just a “translator” for pricing: implied volatility is a derived value.
What shape does the plot of implied volatility against strike price often resemble?
A smile, where implied volatility is higher for OTM or ITM options and lower for ATM options.
Why does the volatility smile exist in the market?
Because the BS model’s assumption of constant volatility and log-normal price distribution doesn’t match real-world price dynamics (large swings and deep ITM/OTM)
How does the volatility smile differ for equity options compared to currency options?
For equities, the smile is often asymmetric with higher IV for OTM puts. For currencies, the smile tends to be more symmetric.
What does a steeper volatility smile imply about market sentiment?
Increased concern for extreme price movements, such as market crashes.
Why do OTM put options generally have higher implied volatility than ATM options?
Because they are often used as protection against sharp price drops, increasing their demand and price.
What is the volatility term structure?
The change in implied volatility depending on the option’s time to maturity.
How does the volatility term structure behave in high-volatility periods and why?
It is typically downward-sloping, with IV decreasing as maturity increases. This could be because immediate uncertainty increases demand for near-term options.
What is the volatility surface?
A 3D representation of implied volatility plotted against both strike price and time to maturity.
What practical insights can traders gain from a volatility surface?
A more detailed understanding of pricing anomalies and market expectations across various strikes and maturities.
How can the volatility surface change during periods of market stress?
The surface can steepen, showing much higher implied volatility for OTM options.