Volatility & advanced strategies
How does VIX pricing relate mathematically to the 30-day implied volatility of S&P 500 options?
By Easy Money Scanner · Educational reference · Not investment advice
The short answer
VIX is calculated from a weighted strip of out-of-the-money SPX put and call option prices across near-term and next-term expirations, representing the market's model-free expected 30-day annualized volatility.
How it works
Cboe's formula sums variance contributions from each listed SPX option weighted by strike spacing, then interpolates between two expirations to produce a constant 30-calendar-day measure, published in real time.
An example
If SPX options imply wide pricing dispersion around upcoming CPI data, VIX rises even before any actual price movement occurs in the S&P 500 index itself.
Risk & limitations
VIX reflects expected future volatility, not a prediction of market direction, and VIX-linked ETPs often diverge significantly from spot VIX due to futures roll costs.
Examples are hypothetical, not trade recommendations. US contract and regulatory references do not automatically apply in Canada. Rules, margin requirements and broker policies can change; confirm them with the relevant authority and your broker.