What Is Implied Volatility (IV)? A Story-First Explanation

On March 16, 2020, SPY opened down 12%.

VIX closed at 82.69 that day — the second highest in history, just behind the 2008 financial crisis.

If you had sold a 30-day SPY put that morning, you would have collected four to five times the usual premium.

Why? Because Implied Volatility (IV) had exploded.

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What IV Actually Is

An option's price is determined by several inputs: stock price, strike, expiration, interest rates, dividends.

These are all known. But there's one variable that isn't — the market's expectation of future volatility.

Take an option's market price and plug it backwards into a pricing model (Black-Scholes). The volatility number you'd need to produce that price is the Implied Volatility.

It's not historical data. It's not a technical indicator. It's what the market is paying right now for uncertainty about how much this stock will move.

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A Concrete Example

NVDA is at $900. Two options, same strike and expiration:

Option A: 30 days out, $850 Put, IV = 40% Option B: Same terms, IV = 80%

Option B costs significantly more.

Because IV 80% means the market is pricing in annualized volatility of 80% for NVDA — that's roughly ±23% over 30 days. IV 40% is ±16%.

Someone buying Option B thinks NVDA might fall hard. If you sell it, you collect the higher premium — but you're betting NVDA won't drop that much.

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How Does IV Move? Expansion and Crush

IV expansion: Fear, uncertainty, events on the horizon. Options get expensive.

Common triggers:

• Earnings (no one knows which way it'll go)
• Macro events (Fed decisions, CPI prints)
• Geopolitical events (2022 Russia-Ukraine, 2020 COVID)
• Company-specific events (FDA decisions, lawsuits, CEO departures)

IV Crush: Uncertainty disappears, IV collapses, options suddenly get cheap.

The clearest example is post-earnings.

Take NVDA's earnings in May 2024:

• Day before: 30-day ATM put IV ≈ 75%
• Day after: same terms, IV ≈ 40%

NVDA beat expectations. Stock jumped 9%. People who bought puts expecting a crash lost money — obviously. But here's the brutal part: people who bought calls also lost money. Even if they got direction right, the IV crush cut their option value nearly in half before the price move could compensate.

That's IV Crush: right direction, wrong outcome. IV dropping on you can cause a loss even when the stock moves your way.

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A Story: GameStop, January 2021

Reddit discovered that GME had 140% short interest. They started buying.

In a few days, GME went from $20 to $483.

At the peak, GME's options IV exceeded 1,000%.

Let that sink in. Annualized volatility of 1,000% means the market was pricing in GME potentially moving to 10x current price — or zero — within a year.

Anyone selling GME puts during that period collected absurd premium. Some of them made fortunes. Others got caught on the wrong side of the squeeze and lost everything.

The lesson isn't "IV can go crazy." The lesson is: IV is an emotion meter, not a rational calculation. It reflects what buyers are willing to pay, and sometimes buyers are panicking.

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Historical Volatility vs. Implied Volatility

There's a related concept called Historical Volatility (HV) — how much the stock has actually moved, calculated after the fact.

• HV: backward-looking, what actually happened
• IV: forward-looking, what the market expects

Here's an observation that holds up over decades: IV runs about 4–5 percentage points above HV on average.

The market chronically overpays for uncertainty. It prices in more volatility than actually happens.

That's the structural edge for options sellers. You sell what the market is overestimating. When realized volatility comes in lower than IV — which it usually does — you keep the difference.

Statistics are on the seller's side over time. Not always. But structurally.

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What Does IV Mean in Practice for Options Sellers?

1. Sell when IV is high: More uncertainty means more premium. Your edge is bigger.

2. Low IV = thin margins: When markets are calm, options are cheap. The same return requires more risk.

3. Be careful around earnings: IV inflates before reports, then collapses after. Opening a position the day before earnings means buying at peak IV. Even if the stock doesn't move against you, the IV crush can hurt your P&L.

4. IV doesn't predict direction: It measures uncertainty, not which way things will go.

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There's one problem with IV as a standalone number: it has no context.

If NVDA's IV is 60%, is that high or low? You don't know — unless you know what it usually is.

That's why IV Rank exists. It puts IV in historical context, telling you exactly where current IV sits relative to the past year.

What Is IV Rank? A Simple Analogy That Makes It Click →