Case Study · Crash Skew
Free to readCrash Skew — March 2020
The COVID crash is the textbook case where all three components fire at once — and the deconstruction shows you which one led.
If GameStop is the case where Slope broke its rule, March 2020 is the case where every component obeyed it — violently. A genuine crash lifts the level, steepens the put-skew, and blows out the tails all together. The value of deconstructing is seeing the order they move in.
The setup
The S&P 500 peaked on February 19, 2020 with an ordinary, gently put-tilted skew. Over the next five weeks COVID drove the fastest 30% drawdown on record — four market-wide circuit breakers between March 9 and 18, and a closing low on March 23, down 34% from the peak. The options surface didn't just rise; its whole shape changed.
Market tops. Normal skew: modest Level, gently negative Slope, mild Curvature.
Four circuit breakers. Level explodes first; then Slope steepens hard (puts bid far above calls); then Curvature blows out as the deep tails get paid.
Closing low, −34% from peak; backstops landing. Curvature peaks; Level begins to roll over while Slope stays steep.
Recovery. Level normalizes, Curvature drains, Slope reverts toward its usual tilt.
What the deconstruction showed
A crash is a Level event first — the entire curve lifts as realized volatility surges. But the signature of fear is in the other two. Slope steepened well beyond its normal tilt: demand for downside protection swamped everything, so puts richened far faster than calls. Curvature spiked as the far-OTM puts — the genuine tail — got bid at a premium beyond even the steep linear skew, because the market was pricing not just "down" but "limit-down." Read as one "skew" number, March 2020 was simply enormous. Deconstructed, it was a Level shock that propagated into a Slope steepening and then a Curvature blowout — and Curvature is what TailDex® would have flagged.
Illustrative of the shape change, not a price chart. The crash lifted Level, steepened Slope (left side far higher), and raised Curvature (convex wings).
The sequence is the lesson. Level moves first (vol rises), Slope second (puts outrun calls), Curvature last and biggest (the tail gets paid). If you only watch a blended skew number you miss that Curvature — the tail premium — peaked near the bottom. That's the component that prices crash protection, and the one that's most overpriced exactly when you're most tempted to buy it.
The trade the components pointed to
Each component has its structure. A Level shock is a long-vol/straddle story. A steep Slope is a put-spread or risk-reversal story. A spiking Curvature — the wings overpriced relative to the linear skew — is a butterfly/condor story: sell the rich tail against the body once the panic peaks. The discipline March 2020 teaches is to know which component is stretched before you pick the structure: shorting the Curvature blowout near the lows is a very different trade from being short the Level into the teeth of the move.
This case study is free. To replay the component series across the crash, you need the historical deconstruction — an Everything capability (single names via ETF + Equities).
See plans →Educational content from Nations Indexes. Event facts (peak/bottom, circuit breakers, drawdown, dates) are historical and verifiable. Component descriptions characterize how the options market priced risk; the figure is an illustrative recreation, not a price chart, and nothing here is investment advice.