What is a Risk Reversal?

By EC Assets Research Team · Published 19 August 2026 · Updated 19 August 2026

Risk Reversal: Two things share this name. As a position it is a long out-of-the-money call financed by a short out-of-the-money put, often struck for zero cost. As a quote it is the volatility difference between those two strikes - the market's standard measure of skew.

What a Risk Reversal Is

The word does double duty, and the two meanings are related but not the same.

As a position, a risk reversal is a long out-of-the-money call paid for by writing an out-of-the-money put. It expresses a directional view with no premium outlay: unlimited participation above the call strike, full downside exposure below the put strike, and nothing in between.

As a quote, the risk reversal is the implied volatility of the out-of-the-money call minus that of the out-of-the-money put at matching deltas — conventionally 25-delta. It is the market's shorthand for skew, and it is how FX options are quoted as a matter of course.

Confusing the two is common. A trader saying "the risk reversal is minus four and a half" is describing the price of skew, not a position anyone holds.

How It Works

The quoted measure:

$$\text{RR}{25\Delta} = \sigma{\text{call }25\Delta} - \sigma_{\text{put }25\Delta}$$

A negative figure means downside strikes are richer than upside ones — the normal state of equity indices, where protection is bid. A positive figure means the reverse, which appears in commodities where the fear is a supply shock upward.

The structure, built at spot 100:

Payoff at expiry

Zero cost between the strikes, symmetric-looking and not symmetric in risk: the upside is a right, the downside is an obligation.

Worked Example

An index trades at 100. The 25-delta put implies 22.5 percent volatility and the 25-delta call 18.0 percent, so the risk reversal quotes at −4.5 volatility points. Puts are markedly richer than calls.

An investor who wants upside exposure without paying premium sells the put and buys the call. Because of that skew, the strikes will not sit symmetrically around spot: the rich put finances a call that must be struck further out, or a nearer put strike must be accepted. The skew is not an inconvenience in the trade — it is the trade's cost, simply expressed in strike distance rather than in cash.

The same quote read as a signal says something else: at −4.5 the market is paying up for protection. When that figure compresses toward zero, demand for downside has faded, which is information about positioning rather than about direction.

When It Applies (and Limitations)

Zero cost is not zero risk. The premium outlay is zero; the exposure is not. A short put carries loss down to zero on the underlying, and margin requirements move against the position exactly when it is losing.

It is a short-volatility position in disguise on one side. Selling the put means being short volatility at the strike where volatility rises most in a sell-off. The position loses on direction and on volatility at the same time.

The delta convention matters. 25-delta is standard but 10-delta risk reversals describe a different part of the wing, and the two can move in opposite directions during stress as the far tail bids independently.

Spot and forward conventions differ by market. FX quotes risk reversals off forward deltas with premium-adjustment conventions that vary by currency pair; equity desks generally do not. Comparing a quote across asset classes without checking convention produces nonsense.

As a signal it is contrarian at extremes and trend-confirming in between. Extreme negative readings have historically coincided with capitulation more often than with the start of a decline, but the relationship is loose enough that using it mechanically is unwise.

Why It Matters for Institutional Investors

It is the standard skew instrument. Any view on the shape of the surface rather than its level is expressed through risk reversals, and desks quote them directly rather than deriving them from two separate options.

It is the mirror image of a collar. A protective collar is long the put and short the call; a risk reversal is the opposite side of that trade. Institutions that systematically collar their equity exposure are supplying exactly what risk reversal buyers demand, which is part of why the skew persists.

It measures the price of fear cheaply. A single number summarises the asymmetry of the entire surface, which is why risk reversal levels appear in positioning dashboards alongside put-call ratios and VIX term structure.

It sizes badly by notional. Because the two legs sit at different strikes with different gammas, notional-matched legs are not risk-matched. Sizing should follow delta or vega, not face value.

References

1. Gatheral, J. (2006). The Volatility Surface: A Practitioner's Guide. Wiley.
2. Natenberg, S. (2015). Option Volatility and Pricing (2nd ed.). McGraw-Hill.
3. Clark, I. J. (2011). Foreign Exchange Option Pricing: A Practitioner's Guide. Wiley.
4. Bank for International Settlements. Triennial Central Bank Survey: OTC Foreign Exchange Turnover. (https://www.bis.org/statistics/rpfx22.htm)