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The world's leading
independent volatility indexes.

Five precision-engineered indexes that strip away the distortions of legacy vol measures — giving you a clean, real-time read on what options are actually pricing.

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VolDex®
A better way to measure option volatility
VolDex® focuses on the options that matter most—at-the-money (ATM) options with near-term expirations—giving a cleaner, more accurate view of implied volatility.

By isolating these highly liquid and actively traded contracts, VolDex avoids the distortion caused by less relevant, far out-of-the-money options. The result is a more precise snapshot of market expectations for price movement and investor sentiment—without the noise.
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CallDex®
A clearer signal of bullish sentiment & expected volatility
CallDex® tracks the cost of out-of-the-money call options to gauge market sentiment for the next 30 days. It uses call options that are one standard deviation out-of-the-money to measure what investors are expecting in terms of both volatility and potential price direction.

Higher CallDex values generally suggest traders are anticipating bigger moves or a possible market rally. Lower values indicate a calmer outlook or reduced interest in upside exposure.
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PutDex®
Focused on downside risk pricing
PutDex® delivers a clear, strike-specific measure of implied volatility by concentrating on one key data point: the normalized cost of a 30-day, one standard deviation out-of-the-money (OTM) SPY put option.

This approach isolates the segment of the options market most directly associated with downside protection, removing the noise from less relevant strike prices. The result precisely indicates market sentiment around tail risk, hedging activity, and bearish positioning.

By zeroing in on these put options—widely used by institutional investors to protect against market declines—PutDex offers valuable insight into how much investors are willing to pay to insure against losses over the next month.
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RiskDex®
A Clear Signal of Expected Market Direction
RiskDex® measures investor sentiment by comparing the normalized cost of 30-day, one standard deviation out-of-the-money (OTM) SPY put and call options. This simple ratio reveals whether the market is more focused on downside protection or upside opportunity — offering a direct view of expected equity direction over the next month.

Unlike traditional volatility indexes, which reflect overall price movement, RiskDex highlights directional bias. A rising RiskDex indicates OTM put prices are increasing at a faster rate than OTM call prices and suggests growing concerns about potential declines; a lower reading signals confidence or complacency.

This makes RiskDex a valuable tool for traders and risk managers seeking clarity on where the market thinks it's headed—not just how volatile it might be.
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TailDex®
A smarter signal for downside risk & tail hedging demand
TailDex® measures the price of deep out-of-the-money put options to assess bearish sentiment and demand for tail risk protection over the next 30 days. By focusing on puts that are three standard deviations OTM, it reflects how concerned traders are about a major downside move, often called a 'tail event'.

Higher TailDex values suggest rising demand for crash protection or increased fear of large selloffs. Lower values imply a calmer market tone and less urgency to hedge against tail risk.
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The Fastest Crash on Record — March 2020

Case Study · This Tool Would Have Told You

Free to read

The Fastest Crash on Record — March 2020

The COVID crash drove the term structure into the deepest backwardation most traders will ever see. The curve was screaming days before the bottom.

Tier: ETF + EquitiesEvent: Feb–Mar 2020Underlying: SPYReading time: 7 min

If August 2024 was a sharp, fast inversion, March 2020 was the curve turned fully upside down for weeks. It is the textbook example of what extreme backwardation looks like — and of how the shape leads the headlines. No VIX needed: read it on VolDex® and TermDex®.

The setup

The S&P 500 peaked at 3,386 on February 19, 2020, with the term structure in ordinary contango — calm, upward-sloping, positive TermDex®. Then COVID went global. Over the next five weeks the index fell 34% to a closing low of 2,237 on March 23 — the fastest 30% drawdown in market history.

Wed, Feb 19, 2020

S&P 500 tops at 3,386. Term structure in calm contango — front below the back.

Mon, Mar 9 — "Black Monday I"

First market-wide circuit breaker. Front-end VolDex spikes; the curve flips into backwardation.

Thu, Mar 12 & Mon, Mar 16

Two more circuit breakers; Mar 16 was the worst single day. Backwardation deepens — front VolDex far above the long end. TermDex® at an extreme low.

Mon, Mar 23

Closing low, 2,237 (−34% from the peak). The Fed's backstops are landing. Front-end VolDex begins to roll over while the back holds — the first hint of normalization.

Late Mar → April

Curve grinds back toward contango as the rally begins. TermDex climbs back through zero.

What the curve showed

This was backwardation at its most violent. Front-week VolDex didn't just rise above the long end — it towered over it, because the market was pricing a genuine, immediate systemic shock. The back end rose too (unlike a one-day scare), but the front rose far more, so the curve sloped steeply down across every tenor. That is the signature of a market that believes the danger is now.

Feb 19 — contango (calm)Mar 16 — deep backwardation
1209060300 VolDex (ATM implied vol) 715306090120150180270360 Days to Expiration (spaced by calendar days) front-end VolDex extreme

Actual SPY VolDex® by tenor: 02/19/2020 (calm contango — front-week ~10, rising to ~15 at one year) versus 03/16/2020 (deep backwardation — front-week ~108, collapsing to ~39 at one year). Tenors spaced by calendar days.

What TermDex® flagged

Positive and calm on Feb 19. By Mar 9 it had flipped negative; through Mar 16 it sat at an extreme low you'd rarely see in a decade. Crucially, TermDex started climbing off the bottom as the front rolled over in the days around Mar 23 — the curve hinted at the turn before price confirmed it.

Do it live

This case study is free to read. To replay the actual curve for these dates and compare it across history, you need historical data — Everything.

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The trade — and the catch

A backwardated curve says the front is rich and the back comparatively cheap; the snap-back structure is a calendar — short the rich front-week ATM vol, long a further-dated ATM option. But March 2020 carries the warning that comes with extreme inversions: when stress is systemic, the front can stay bid for weeks and realized volatility can be enormous. A short-front structure put on too early, too big, gets run over.

Regime
Deep backwardation (TermDex® at a multi-year extreme)
Structure
Calendar / diagonal, ATM legs — but smaller, and patient. The edge is real; the timing risk is severe.
Confirmation
Wait for TermDex to start climbing off the bottom (front rolling over) before pressing the snap-back.
Risk
Systemic stress can keep the front bid for weeks; realized vol can overwhelm a short-front trade. Size for the curve being wrong about "temporary."

The lesson

March 2020 is the case that teaches respect for the front end. The shape told you the regime in real time — calm, then violent inversion, then the first roll-over before the bottom. But it also shows that reading the regime and surviving it are two different skills. The curve gives you the map; position size keeps you in the game.

Educational content from Nations Indexes. VolDex® and TermDex® are registered marks of Nations Indexes. Event facts (peak/bottom levels, circuit breakers, dates, drawdown) are historical and verifiable. The curve description characterizes how the options market priced risk on those dates; the figure is an illustrative recreation of the shape change, not a price chart, and nothing here is investment advice or a guarantee of any outcome.