Hermēs DocumentationImplied vs Realized Volatility
IV is the market's quote for future movement, RV is what actually happened, and their gap (the variance risk premium) is the core rent of the options market — plus how to read it inside HermesGEX.
One-line positioning
Realized volatility (RV) = the rear-view mirror: how much price actually moved. Implied volatility (IV) = the price tag on the windshield: what the market charges right now for future movement.
Mantra: IV is a price, not a prophecy.
High IV = insurance is expensive, the market is pricing big movement; low IV = insurance is cheap. It carries no direction — don't read "IV spiked" as "it's going to fall."
Section 1: Two volatilities
| Realized vol (RV) | Implied vol (IV) | |
|---|---|---|
| Direction | Backward-looking (history) | Forward-looking (expectation) |
| Source | Computed from actual price series | Backed out of option prices |
| Meaning | "How much it really moved" | "What the market charges for future movement" |
| Speed | Slow, known only after the fact | Fast, ticks with every quote |
Key: IV is not someone's forecast of volatility. It's the number you get by inverting the pricing model on current option prices. It's the market's "quote for future movement," voted with real money.
Section 2: VRP — the core rent of the options market
Put IV next to subsequent RV and a long-run regularity appears:
Variance risk premium (VRP) = IV − subsequent RV, usually positive over time.
Options are insurance. Buyers pay a premium for fear; sellers carry the tail risk and collect that rent. So the volatility the market prices (IV) usually sits slightly above the volatility that actually happens (RV) — the structural edge of the seller.
Mechanism (not prediction):
Put / call buyers → pay a premium for "insurance" → lift IV
Dealers/funds selling → collect the premium, carry risk → harvest VRP over timeBut VRP turns negative — which is exactly why it's "unfalsifiable yet useful":
- Calm periods: IV > RV, VRP positive, vol sellers collect rent.
- Shock periods (crash / macro black swan): actual movement instantly exceeds the prior pricing, RV > IV, VRP flips negative, vol sellers get harvested.
Note: we don't predict when it flips. We only state the mechanism — once actual movement exceeds what the market had priced, short-vol positions are forced to close at a loss, which itself amplifies movement. That is the short-gamma feedback loop said another way.
Section 3: How traders use it (mechanism, not direction)
Don't read IV as an up/down signal. Read it as "how expensive is insurance right now, and which structure is structurally favored":
| IV environment | Mechanistic meaning (conditional) | Structurally favored side |
|---|---|---|
| High IV Rank (insurance rich) | Sellers collect thick rent; if RV doesn't keep up, IV tends to mean-revert lower | Short-vol structures (spreads / iron condors), provided RV doesn't blow out |
| Low IV Rank (insurance cheap) | Buyers pay little; IV lifts easily once an event arrives | Long-vol structures (long vega), provided there's a real catalyst |
| IV rising into an event | Market pricing a known catalyst (earnings / FOMC / CPI) | — |
| IV crush after the event | Uncertainty resolves → IV collapses instantly | The pre-event seller (harvests the crush), but carries directional risk |
IV crush is the most common "mechanistic necessity."
Uncertainty around a known time (earnings / FOMC) bids IV up beforehand; once the result lands and uncertainty disappears, IV must collapse (crush) — regardless of which way price goes. That's not a forecast, it's the identity "uncertainty gone → its price goes to zero."
Section 4: 👀 Where to see it in HermesGEX
| What you want | Where | How to read it |
|---|---|---|
| How rich IV is now | Insight Rail · IV Rank bar | Bar near full = IV at the top of its history, insurance rich; near empty = cheap. Rank < 20 favors buyers, > 78 favors sellers |
| Whether VRP is positive or negative | Insight Rail · VRP sparkline card | A 30-point sparkline > 0 = implied vol is collecting rent (sellers favored); flipped negative = realized has overtaken implied, short vol is dangerous |
| The IV-implied daily range | Main chart · Event Mode ±1σ / ±2σ bands | The range the market prices for today; the σ bands are IV translated into price |
| Overall vol pricing level | market-context · VIX family | VIX is 30-day option IV indexed — the fear temperature |
| Market's probability per level | Options Desk · Vol Intelligence (Breeden-Litzenberger implied probability) | The probability density inverted from option prices — how much weight the market gives each level (Ultra) |
Overlay the σ bands on the GEX walls. Event Mode's ±1σ band tells you "roughly how far the market prices today's move"; the GEX Call/Put Walls tell you "where dealer hedging will push back." Where they overlap is the day's highest-conviction reaction zone.
Section 5: The three most common traps
1. High IV ≠ bearish. IV is the price of movement, with no direction. Declines often come with IV spikes, but you can't run that backward to infer direction from high IV.
2. IV Rank ≠ absolute IV. A 20% IV is high for some names and low for others. Always read the Rank / percentile relative to the name's own history, never the raw number.
3. Selling high IV is not a free lunch. VRP is positive over time, but one negative-VRP event can erase months of rent. Short vol always needs tail risk control — never sell naked.
Next steps
IV is "a single number," but the market does not quote the same IV across different expiries or different strikes. The next two chapters split that number into two dimensions: time (term structure) and cross-section (skew).
Chapter mantra: RV is the rear-view mirror, IV is the price tag; IV − RV = VRP is the seller's long-run rent, but it harvests sellers when it flips; high IV only means insurance is expensive, never a direction.
Frequently asked questions
What is the difference between implied and realized volatility?
Realized volatility (RV) is a backward-looking statistic — how much price actually moved over a past window. Implied volatility (IV) is a forward-looking quote — backed out of current option prices, it's the market's pricing of future movement. RV reads the rear-view mirror; IV reads the price tag on the windshield.
Why is implied volatility usually higher than realized volatility?
Because options are insurance. Buyers pay a premium for fear; sellers take the risk and collect rent. So IV usually sits slightly above subsequent RV over time — that gap is the variance risk premium (VRP). It turns negative in stretches, when actual movement suddenly exceeds what the market had priced, and that's when sellers lose.
Is high implied volatility a bearish signal?
No. High IV only means insurance is expensive and the market is pricing large movement — it carries no direction. IV often spikes during declines, but high IV by itself predicts nothing about up or down. It's the price of movement, not a prophecy of it.
Volatility & Dealer Flows — Overview
Implied vol, term structure, skew and second-order Greeks rebuilt as "what dealers are forced to do" — each wired to HermesGEX.
Volatility Term Structure
The same name quotes different IV at different expiries — near vs far, what an inversion means, and how to read it with the VIX family in HermesGEX.