Volatility skew refers to the pattern where implied volatility differs across options with different strike prices but the same underlying asset and expiration date. Rather than all options having identical volatility expectations, the market prices certain strike prices with higher or lower volatility assumptions. This creates a skewed distribution that looks like a smile or a smirk on a volatility chart.
How It Works
In a perfect world, all options on the same stock expiring on the same day would have equal implied volatility. In reality, they don't. After market crashes, traders demand higher prices (higher implied volatility) for out-of-the-money put options as protection against further downside. Simultaneously, far out-of-the-money calls may have lower volatility pricing. This asymmetry creates the skew.
The skew exists because different market participants have different hedging needs and risk concerns. Institutional investors buying protective puts drive up volatility for lower strikes, while speculators selling far out-of-the-money calls depress volatility at higher strikes. Supply and demand for risk protection at different price levels directly shapes these patterns.
Why It Matters for Investors
Understanding volatility skew helps you identify mispriced options and better understand market sentiment. A steep skew suggests the market is worried about downside moves—put options are expensive relative to calls. A flatter skew indicates more balanced risk expectations. For portfolio managers, this information helps with hedging decisions and options strategy selection.
Options traders can exploit skew patterns. If you believe the market is overpricing downside protection, you might sell puts and buy calls—taking the opposite side of the market's fear trade. Conversely, if you expect volatility patterns to normalize, skew trades can be profitable when positioning reverses.
Example
Consider a stock trading at $100 with options expiring in 30 days. The $95 put (out-of-the-money) might have 35% implied volatility, the $100 call (at-the-money) might have 25% implied volatility, and the $105 call (out-of-the-money) might have 20% implied volatility. This downward slope from left to right is the skew—the market expects bigger downside moves than upside moves relative to current pricing, so it charges more for downside protection.
Key Takeaways
- Volatility skew shows that implied volatility varies across strike prices for the same expiration, reflecting different market hedging demands
- Steeper skews typically appear after market stress when investors prioritize downside protection
- Recognizing skew patterns helps identify trading opportunities and informs better hedging decisions
- Skew changes over time as market sentiment and risk perceptions shift