Volatility Skew

Q: What is volatility skew?

Skew is the difference in IV between OTM puts and calls at the same delta. Puts typically have higher IV (positive skew) because investors pay more for downside protection.

Q: What does high skew mean?

High skew means strong demand for downside protection — either institutional hedging or fear. Increases during sell-offs, decreases during calm periods.

Q: Why does Volatility Skew matter for trading?

Volatility skew shows how much more expensive puts are than equidistant calls — effectively, how much fear the market is pricing in. Steep skew is a high-fear / low-complacency signal; flat or inverted skew is a high-complacency / low-fear signal. Traders use skew extremes to time contrarian trades and to select strategies that trade the skew surface directly.

Q: When is Volatility Skew good versus bad for a trader?

Very steep skew is good for contrarian longs and short-put spread sellers — fear is overpriced. Very flat skew is good for put buyers and hedge initiators — protection is cheap. Normal equity skew has no actionable signal; use other inputs.

Canonical definition, formula, interpretation, and API reference.

Definition

Asymmetry in implied vol between OTM puts and OTM calls at the same delta. High skew = expensive downside protection.

Formula

Skew_25d = IV(25d put) - IV(25d call)

Measured at the 25-delta level. Also includes smile_ratio and tail_convexity.

Inputs

25d put IV25d call IVATM IV

Output

skew_25dsmile_ratiotail_convexity

Interpretation

High skew (>5pts): institutional hedging demand
Low skew (<2pts): calm, balanced markets
Negative skew (rare): squeeze/melt-up conditions

API Reference

Endpoint

GET /v1/volatility/{symbol}

Tier

Growth+

Response field

skew_profiles[].skew_25d, smile_ratio

Why Volatility Skew Matters for Trading

TL;DR

Skew is the asymmetry between put and call IV at equal OTM distance. Steep = crash fear priced in. Flat = complacency. Extremes mark regime shifts.

What it measures: Difference in IV between the put wing (e.g. 25-delta put) and the call wing (e.g. 25-delta call).
What it signals: How much traders are paying for downside protection relative to upside participation.
Why we measure it: Skew is a direct read on fear vs greed in the options market. It leads realised moves more often than it lags.
Who uses it: Vol traders, macro traders, contrarian investors, tail-risk hedgers.

How to read Volatility Skew

Very steep skew

Deep fear priced in
Often marks local bottoms
Contrarian long setups
Put overpricing = short-put edge

Good for: contrarian longs, short-put spreads

Very flat / inverted skew

Complacency dominates
Often precedes sharp selloffs
Protection is cheap — buy it
Bear warning sign

Bad for: short downside — good for: put buyers

Normal equity skew

Typical index skew slope
No edge in shape
Trade on other factors
Default reading

Baseline

Rules of thumb

Equity skew is always negative. Puts are always richer than equidistant calls. Magnitude matters, not sign.
Compare across names. Single-stock skew is usually flatter than index skew. Don't compare directly.
Pair with term structure. Steep front skew + backwardation = stress regime. Flat skew + contango = complacency.
Watch extremes historically. Skew percentile rank matters more than absolute level.
Event days steepen skew. Earnings and CPI steepen skew temporarily; back it out of your signal.