# Vega Hedge with Calendar Spreads: A Term-Structure Plan

Build a calendar-spread Vega hedge by expiry bucket, calculate hedge ratios, test nonparallel IV moves, and plan front-expiry and assignment handling.

Canonical: https://wiki.fcontext.com/options/vega-hedge-calendar-plan/
Fact checked: 2026-07-22

> For educational purposes only; not investment advice.

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## Direct answer

A **calendar-spread Vega hedge** uses options with different expirations to change a portfolio's sensitivity to implied volatility by maturity. A common long calendar sells a nearer option and buys a farther option of the same type and strike. Because the farther option often has greater Vega, the spread is frequently net long Vega at entry.

That net number is only a parallel-shift estimate. The near and far IVs are separate surface points and can move by different amounts. A calendar can reduce aggregate Vega while adding term-structure basis risk, front-expiry Gamma, Theta, Delta, liquidity, and assignment exposure. A hedge plan therefore needs expiry buckets and full scenarios, not just “net Vega near zero.”

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## Hedge construction

First normalize every leg to dollars per one volatility-point move:

`position Vega = displayed per-share Vega × signed contracts × multiplier`

Then group Vega by expiration and, where material, by strike or Delta. Report both gross and net values. For a proposed calendar:

`calendar Vega = far-leg Vega − near-leg Vega`

For a simple parallel-shift target, an initial integer hedge count is:

`calendar count ≈ (target net Vega − current net Vega) ÷ Vega per calendar`

Round toward the risk limit, not mechanically to the nearest contract, and recalculate Delta, Gamma, Theta, margin, and liquidation value after adding the spread. A ratio that neutralizes today's Vega becomes stale when spot, IV, time, or either leg's moneyness changes.

Next replace the parallel assumption with a scenario matrix. Shock near IV and far IV independently, move spot toward and away from the strike, advance the clock, widen Bid/Ask spreads, and reprice both legs. Include the short option's expiration and the decision to close, roll, accept settlement, or retain the far option. A roll closes one hedge and opens another; it is not a continuation at unchanged risk.

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## Parallel and nonparallel IV examples

Suppose one long calendar has far-leg Vega `+$0.145` and short near-leg Vega `−$0.082` per share per volatility point. With a 100-share multiplier:

`net Vega per calendar = ($0.145 − $0.082) × 100 = +$6.30 per point`

A portfolio has net Vega `−$126` per point under a parallel-shift summary. Ignoring integer and other risks for the first pass, `20` calendars add `20×$6.30=+$126`, producing approximately zero aggregate Vega.

But the hedge contains gross far Vega of `+$290` and gross near Vega of `−$164` per point. If both expirations rise `4` points, the calendar package's Vega-only estimate is:

`20 × 100 × [($0.145×4) − ($0.082×4)] = +$504`

If near IV rises `7` points while far IV rises only `2`, the same package estimate is:

`20 × 100 × [($0.145×2) − ($0.082×7)] = −$568`

The package labeled “long Vega” loses in the second scenario because the short bucket moves more. These are local estimates; changing Vega, spot, skew, time, and execution require full repricing. The original portfolio's bucket exposures must be shocked alongside the hedge before judging effectiveness.

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## Operational hedge plan

- Inventory every option, stock position, multiplier, expiry, strike, exercise style, and signed quantity from broker records.
- Normalize Vega to one volatility point and dollars, then split it into near, event, medium, and long-dated buckets.
- Identify the actual risk to reduce: a parallel shift, one event expiry, a term-slope move, or a specific strike region.
- Select liquid calendar legs that overlap that risk. Similar net Vega in unrelated expirations may be a poor hedge.
- Calculate an initial ratio, round to tradable contracts, and report remaining net and gross Vega.
- Fully reprice spot gaps plus near/far IV shocks; do not add Greek estimates across large moves as if they were constant.
- Check Delta, Gamma, Theta, Vomma, skew, margin, debit, maximum stress loss, and executable Bid/Ask after the hedge.
- Set review triggers based on bucket Vega, spot distance from strike, days to front expiry, event dates, spread width, and stress loss.
- Before front expiry, decide whether to close both legs, close or roll the short leg, or retain the far option. Re-underwrite every roll.
- For American equity options, monitor early assignment, especially deep-in-the-money short Calls near an ex-dividend date.
- Do not assume the far option automatically covers assignment. Exercise, assignment, stock delivery, and broker cutoffs are separate processes.
- Record hedge slippage and realized P&L by Delta, time, surface, and execution so an ineffective basis hedge is not repeatedly renewed.

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## Common misconceptions

- **“Net Vega zero means volatility-neutral.”** Separate expirations and strikes can move differently while gross exposure remains large.
- **“A calendar is always long Vega.”** Its sign and magnitude change with spot, time, moneyness, and model inputs.
- **“Longer-dated IV rising helps regardless of spot.”** Delta, Gamma, skew, and moneyness changes can outweigh the Vega estimate.
- **“The short leg provides free Theta.”** Front Gamma, event jumps, assignment, and liquidity are the price of that decay exposure.
- **“One hedge ratio works until expiration.”** All Greeks and the surface change continuously.
- **“Rolling preserves the hedge.”** A roll realizes one position and creates a new contract with new risk and cost.
- **“Midpoint Greeks describe executable protection.”** Wide or asynchronous quotes can make the hedge expensive or unavailable when needed.

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## Related topics

- [Calendar Spread](/options/calendar-spread/)
- [Vega](/options/vega/)
- [Implied Volatility](/options/implied-volatility/)
- [Option Stress Testing](/options/option-stress-testing/)

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## Authoritative sources

- [Vega](https://www.optionseducation.org/advancedconcepts/vega) — Options Industry Council
- [Calendar and Diagonal Spreads](https://www.optionseducation.org/news/september-webinar-key-takeaways-what-are-calendar-diagonal-spreads) — Options Industry Council
- [Options Assignment](https://www.optionseducation.org/referencelibrary/faq/options-assignment) — Options Industry Council
- [Characteristics and Risks of Standardized Options](https://www.theocc.com/company-information/documents-and-archives/options-disclosure-document) — Options Clearing Corporation