Skew Trading: Profiting From the Volatility Smile

Key Takeaways

• Options skew trading takes a view on how implied volatility differs across strikes, not on its overall level.
• Equity index skew is typically negative, with downside puts priced richer than upside calls since 1987.
• The common mistake is treating skew as a free signal while ignoring the vega and delta it carries.
• A risk reversal is the standard structure for expressing a directional skew view.

What Options Skew Trading Is

Volatility skew is the pattern in which options at different strikes carry different implied volatilities. In equity indexes, out-of-the-money puts usually have higher implied volatility than out-of-the-money calls, a downward-sloping shape often called a smirk. When both wings are elevated, the curve looks like a smile.

Options skew trading positions for changes in that curve. A trader can sell the rich side and buy the cheap side, bet the slope steepens or flattens, or trade one strike against another. The aim is to profit from the relative pricing of strikes, ideally hedged so the overall level of volatility and the direction of the underlying matter less.

The Intuition

Skew exists because risk is not symmetric. Since the 1987 crash, equity investors have paid a persistent premium for downside puts as crash insurance, while showing less appetite to overpay for upside calls. The Options Industry Council notes that before 1987 skew was nearly absent.

A skew trader asks whether that premium is too rich or too cheap right now. If downside puts look overpriced relative to upside calls, the trader sells the put skew and buys the call side, collecting the imbalance. The bet is on the relationship between strikes, not on market direction, so the position is usually structured to limit directional and net-volatility exposure.

How It Works

The most direct skew structure is a risk reversal: sell an out-of-the-money put and buy an out-of-the-money call at similar deltas, or the reverse. The cost of a risk reversal reflects the skew between the two strikes:

risk reversal value is driven by (call implied vol - put implied vol) at matched delta

When put implied volatility sits well above call implied volatility, selling the put and buying the call can be done at a credit or near zero cost, monetizing the skew. The position carries delta, so traders often hedge with the underlying to focus on the skew rather than direction.

A second approach trades the slope itself with vertical spreads or ratio spreads across strikes, sizing each leg so net vega is small. This isolates the change in the curve's shape. Because skew shifts with market stress, often steepening as fear rises, the trade has an embedded view on sentiment as much as on pricing.

Worked Example

Suppose an index trades at 100. The 25-delta put implies 24% volatility, while the 25-delta call implies 18%. The skew, measured as the risk reversal, is:

25-delta risk reversal = 18% - 24% = -6 volatility points

A trader who thinks the 6-point downside premium is excessive sells the 25-delta put and buys the 25-delta call, executed near zero cost because the richer put funds the cheaper call. The position is then delta hedged with a short index position to mute direction.

If markets stay calm and the put skew normalizes toward minus 3 points, the sold put cheapens faster than the bought call, and the trade gains on the skew compression. If a sell-off hits, put skew steepens toward minus 10 points, the sold put gets more expensive, and the position loses.

Common Mistakes

1. Ignoring the directional tilt. A risk reversal that is short puts and long calls is implicitly long the underlying. Without a delta hedge, a skew trade can become an accidental directional bet.

2. Forgetting that skew steepens in crashes. Selling downside puts to harvest skew is short crash risk. The position earns small premiums in calm markets and can lose heavily when fear spikes and put skew explodes.

3. Mismatching deltas or expirations. Comparing a 25-delta put to a 10-delta call, or a front-month put to a back-month call, measures the wrong thing. Skew is only meaningful at matched delta and tenor.

4. Overlooking net vega. A skew structure can carry residual vega if the legs are not balanced, turning a shape bet into a level bet on overall volatility.

5. Trading skew without a catalyst. Skew is sticky and can stay rich or cheap for a long time. Expecting quick mean reversion without a reason often leads to bleeding the position through carry.

Frequently Asked Questions

What is options skew trading in simple terms? Options skew trading bets on the difference in implied volatility between strikes, such as downside puts versus upside calls. It is a view on the shape of the volatility curve, not on the market going up or down.

How does options skew trading affect investment decisions? It lets a trader monetize or hedge the premium investors pay for downside protection. A desk that judges put skew to be too rich can sell it and buy upside, while a hedger worried about a crash may pay up for steep skew on purpose.

What is a real-world example of options skew trading? When 25-delta put implied volatility sits several points above the 25-delta call, a trader sells the put and buys the call as a risk reversal, then delta hedges to focus on the skew rather than direction.

How can investors use options skew trading effectively? Match deltas and expirations when measuring skew, delta hedge to remove the directional tilt, balance the legs so net vega stays small, and size for the fact that skew steepens violently in sell-offs.

How is skew trading different from volatility arbitrage? Volatility arbitrage bets on implied versus realized volatility, the level. Skew trading bets on the relative pricing across strikes, the shape of the volatility curve.

Sources

1. The Options Industry Council. Volatility Skew and Options: An Overview. https://www.optionseducation.org/news/volatility-skew-and-options-an-overview-1
2. Cboe. The Power of the Risk-Reversal. https://www.cboe.com/insights/posts/the-power-of-the-risk-reversal/
3. Damodaran, A. Option Pricing Theory and Applications. NYU Stern. https://pages.stern.nyu.edu/~adamodar/pdfiles/country/option.pdf
4. Corporate Finance Institute. Volatility Arbitrage. https://corporatefinanceinstitute.com/resources/derivatives/volatility-arbitrage/

Disclaimer

This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.