Volatility Surface

Markets discovered that different options face different risks. OTM puts face crash risk (need higher IV), longer-term options face more uncertainty (typically higher IV). Supply and demand also varies - institutional hedging creates demand for certain strikes. The surface reflects all these factors.

For casual traders, checking weekly is sufficient. For active options traders, daily monitoring helps identify opportunities. The surface tends to move slowly most of the time but can shift rapidly during market stress. Event days (FOMC, earnings) warrant close attention.

Usually, but not always. Most equity indices and stocks have negative skew (downward sloping - puts more expensive). However, certain situations can invert this: takeover targets (calls expensive for upside), some commodities (supply disruption risk), and occasionally during strong rallies. Always check current skew.

During crises, several things happen: (1) Overall level rises dramatically (VIX spikes), (2) Skew steepens (even more put demand), (3) Term structure inverts to backwardation (near-term fear exceeds long-term), (4) Smile becomes more pronounced. Understanding this helps prepare for stress scenarios.

Basic surface analysis can be done with broker platforms that show IV across strikes and expirations. Many brokers display volatility charts. For more sophisticated analysis, services like LiveVol, ORATS, or OptionMetrics provide detailed surface data. Start with free/included tools and upgrade as needed.

Use historical percentiles. Calculate where current 25-delta skew falls relative to the past 1-2 years. Above 80th percentile suggests steep skew (potential flattening trade). Below 20th percentile suggests flat skew (potential steepening trade). Remember that skew has structural reasons to exist - it won't go to zero.

When skew exists, delta hedging becomes more complex due to vanna. As spot moves, your delta changes not just from gamma but also because the skew structure affects delta at different spots. This is why understanding vanna matters for large positions. Delta-hedged positions still have skew/vanna exposure.

VIX itself (spot) isn't directly tradeable. VIX futures and options allow trading term structure and level views. VIX futures curve shows term structure directly. VIX options have their own smile. Be aware: VIX products behave differently from equity options and require specific understanding.

Events create localized effects. FOMC tends to elevate IV in the expiration containing the meeting and can flatten term structure. Earnings spike IV in that specific expiration. These effects create 'kinks' in the surface that normalize post-event. This creates calendar spread opportunities around events.

Trading level means betting on overall IV direction (long or short vega across the surface). Trading skew means betting on relative IV between puts and calls, trying to be neutral to overall level. They can be separated by careful structure selection (risk reversals isolate skew; straddles capture level).

Vanna and volga exposures are hedged by trading other options. Vanna can be reduced by risk reversals or ratio spreads. Volga can be managed with butterfly positions. Professional desks monitor these Greeks continuously and use portfolio-level optimization to achieve desired exposures. Perfect hedging is costly, so risk limits are used.

The variance risk premium (implied > realized) is driven by: (1) Insurance demand - investors pay for vol protection, (2) Risk aversion - utility of hedging exceeds fair actuarial value, (3) Jump risk - implied vol accounts for rare jumps not captured by realized, (4) Volatility of volatility - vega convexity creates value. Research suggests ~2-4 vol points on average for SPX.

Implied correlation can be backed out from: ρ_implied = (σ²_index - Σw²ᵢσ²ᵢ) / (2Σwᵢwⱼσᵢσⱼ), where weights and vols are for index components. In practice, simplified approximations are used. Compare to realized correlation (from historical returns) to identify dispersion opportunities. CBOE publishes implied correlation indices.

Decompose P&L into: (1) Delta P&L from spot move, (2) Vega P&L from parallel IV shift, (3) Vanna P&L from spot-IV interaction, (4) Skew P&L from skew change, (5) Term structure P&L from curve change, (6) Theta from time decay. This requires calculating sensitivities to each dimension and multiplying by realized changes.

Mean reversion exists but with significant caveats: (1) Timing is highly uncertain - extremes can persist, (2) The 'mean' itself shifts over time (structural changes), (3) Tail events can cause permanent regime shifts, (4) Carry/theta bleeds while waiting for reversion. Professional traders size for reversion taking longer than expected and use stops to limit damage from non-reversion scenarios.