What is implied volatility?
Implied volatility is the annualised movement that an option's traded price implies, once strike, time to expiry and the underlying's level are accounted for. It is not a forecast of direction. A higher reading means the market is paying more for the same expected range; a lower one means it is paying less. It is quoted as a percentage a year, which is why it needs converting before it means anything over a few days.
What does at-the-money implied volatility mean?
It is the reading at the centre of the option chain, where the strike matches where the market prices the underlying at expiry. That centre is the forward, not the current spot price, and the two differ by the cost of carry — enough to sit a couple of strikes apart on a monthly expiry. Using the forward keeps the figure comparable from one session and one expiry to the next.
Why do the call and the put show the same implied volatility here?
Because with the correct centre they should. Put-call parity is an arbitrage relationship, not a model, and it means one volatility reprices both legs of a strike. Where an exchange or broker shows two different figures at the same strike, the difference measures bid-ask friction and stale quotes on the less liquid leg. This page shows that difference separately, as a data-quality reading rather than as a signal.
How do I turn an implied volatility figure into points?
Multiply the underlying's level by the volatility and by the square root of the time to expiry in years. This page does that for you and prints the result as the expected move. It is a one-standard-deviation figure, so roughly two sessions in three finish inside it and one does not — and the arithmetic says nothing at all about which side of the range that move lands on.
Why is there no IV Rank or IV Percentile on this page?
Both compare today's reading against about a year of daily closes, and this site keeps intraday session history rather than years of it. A rank computed from a few weeks would be a different statistic wearing the same name: it depends on the highest and lowest readings in its window, so a short window overstates it and a single quiet spell can move it dramatically without today's reading changing at all.
What is implied volatility?
Implied volatility is the annualised movement the option market is currently pricing into a contract, derived by working the Black-Scholes formula backwards from the traded premium. It is an expectation, not a measurement of past movement. When implied volatility rises, premium expands for the same spot price; when it falls, premium contracts.
