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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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When the Skew Flipped — GameStop, January 2021

Case Study · The Skew Flipped

Free to read

When the Skew Flipped — GameStop, January 2021

Equity skew is almost always tilted toward puts. For a few days in January 2021, relentless call buying flattened it — the kind of regime the Slope component is built to catch.

Tier: ETF + EquitiesEvent: Jan 2021Underlying: GMEReading time: 6 min

The cleanest way to understand the Slope component is to watch a name where it broke its own rule. In a normal stock, Slope is firmly negative — puts trade richer than calls because everyone wants downside protection. The January 2021 meme squeeze inverted that intuition: the crowd wanted upside, violently, and the skew told you so before the headlines did.

The setup

Through the back half of January 2021, a coordinated retail bid turned GameStop into a short-and-gamma squeeze. Options activity exploded and implied volatility went vertical. From January 21 to January 27 the stock rose roughly 1,500%, peaking around January 27–28 before brokers restricted trading. The options market wasn't pricing a possible crash — it was pricing a possible moonshot.

Thu–Mon, Jan 21–25, 2021

Price acceleration; option volume surges; IV spikes. Level explodes; Slope starts flattening as call demand floods in.

Tue–Wed, Jan 26–27

Squeeze peaks (~+1,500% on the run). Slope flattens hard toward zero — on the hottest squeeze names it briefly inverted, calls bid like puts. Curvature blows out as both wings get paid.

Thu–Fri, Jan 28–29

Trading restrictions; the bid breaks. Level stays extreme but begins to recede; Slope reverts back toward its normal negative tilt.

What the deconstruction showed

Three things happened at once, and the deconstruction separated them. Level went to a reading you'd almost never see in a major name — overall IV in the hundreds of percent. Slope, normally deeply negative, flattened dramatically toward zero as call IVs caught up to and rivaled puts; the structural put-skew temporarily dissolved. Curvature spiked too — both tails were bid, because nobody knew whether the next move was a vertical melt-up or an air-pocket down. A single "skew" number would have just said "huge." The components told you it was a demand-for-calls regime, not a fear regime.

Normal — put skew (Slope ≪ 0)Squeeze — flattened / call-bid
highlow IV OTM putsATMOTM calls Strike (log-moneyness) calls bid as hard as puts — Slope ≈ 0

Illustrative of the regime change, not a price chart. The squeeze lifted the whole curve (Level) and flattened the put-skew (Slope toward zero), with both wings bid (Curvature).

What the components flagged

Slope is the tell. A name whose Slope flattens toward zero — or inverts — is a name where the crowd is paying up for calls, not puts. That's the structural signature of a squeeze, and it shows up in the Slope component while price is still going vertical. RiskDex®, which Slope drives, would have screamed the same thing.

The trade the components pointed to

A flattened or inverted Slope is a relative-value statement: calls are rich versus their usual discount to puts. The clean expression is a risk reversal read in reverse — when the normal put-over-call premium has vanished, structures that are long the (now-cheap-relative) put skew and short the (now-rich) call skew carry the edge, sized for the fact that a squeeze can stay irrational longer than you can stay solvent. The exploding Level and Curvature are the warning: this is not a quiet mean-reversion; it's a violent regime where short-vol of any kind is dangerous.

Do it live

This case study is free. To deconstruct a single name like GME yourself you need ETF + Equities; to replay the components across the squeeze, the historical series is an Everything capability.

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Educational content from Nations Indexes. Event facts (squeeze dates, the ~1,500% run, IV surge, trading restrictions) 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.

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