Options 101·Beginner··5 min read

Volatility skew explained: what it says about institutional positioning

Volatility skew explained: the shape of the IV curve across strikes is itself a signal. Reading skew is reading fear and conviction.

Volatility skew explained in one line: implied volatility is not one number, it is a curve. Different strikes on the same underlying trade at different implied volatilities. The shape of that curve is called skew, and reading it is one of the highest-information-density skills in options.

The default shape

For equity indices, OTM puts typically trade at higher implied volatility than OTM calls. This is the 'put skew' or 'volatility smirk' - a structural reflection of the fact that crashes are sharper than melt-ups, and that funds bid up insurance against tails.

How skew shifts under stress

When markets are calm, put skew is moderate. When stress builds, put skew expands - the cost of downside insurance rises relative to upside speculation. A widening skew without a falling index is institutions building downside protection while the price action still looks fine.

Single-name vs index skew

Single names often show the opposite of index skew. For mid-cap growth stocks, OTM calls often trade at higher IV than OTM puts - the 'call skew' reflects retail speculation on upside. When call skew on a stock is rising sharply, retail is bidding up lottery tickets.

The trade implications

  • Wide put skew + flat market: institutional fear building, potential downside catalyst lurking.
  • Collapsing put skew during a rally: complacency, downside protection getting cheap.
  • Rising call skew on a single name: speculation building, often around a catalyst.
  • Flat skew across the board: regime of indifference, often precedes vol expansion.

Why this matters even if you do not trade skew

Skew is a leading indicator of positioning shifts. By the time skew is at extremes, the broader market is usually still pricing in the old regime. Watching it is watching what serious vol traders are doing, not what is in the news.

Volatility skew explained on its own is a static picture. It gets useful next to the flow that moves it: unusual options activity shows which strikes are being bought, and gamma exposure shows what dealers have to do about it.