net -vanna/charm

• Net Charm: Cumulative Charm exposure across all strikes ($MM/hr).
• Net -Vanna: Cumulative -Vanna exposure across all strikes ($MM until expiry).

Net -Vanna and Net Charm measure the aggregate passive hedging pressure generated by daily options transactions as contracts approach expiration:

• Positive Value: Customers gain deltas into expiration. Dealers lose deltas and must buy underlying shares to maintain neutrality.
• Negative Value: Customers lose deltas into expiration. Dealers gain deltas and must sell underlying shares to maintain neutrality.

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Hedging Mechanics Example

Consider a scenario dominated by customer-sold out-of-the-money (OTM) calls:

1. As expiration approaches, the extrinsic value of these OTM calls decays toward zero.
2. This decay makes customer portfolios less short (gaining delta).
3. To maintain delta neutrality, dealers must continuously purchase underlying shares into the close.
4. If spot price rallies into the short strike, the contract moves at-the-money, and decay-driven buying subsides.

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Thresholds & Timing Dynamics

Hedging intensity depends on contract moneyness, total dollar exposure, and time remaining:

• Magnitude Thresholds (SPX): Net -Vanna becomes statistically significant when absolute exposure exceeds $800MM, particularly during the final hour of trading (3:00 PM–4:00 PM ET). Exposures exceeding $1,000MM impact price action earlier in the session.
• Extreme Reversals: Large imbalances frequently drive end-of-day mean reversion or squeeze continuation as algorithmic participants anticipate structural dealer rebalancing.

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Market Energy & Volatility Regimes

Net Vanna and Net Charm quantify potential market energy:

• Neutral Readings: Dealer hedging obligations remain minimal. Price action is more likely to consolidate or follow independent orderbook flow.
• Extreme Imbalances: Imminent dealer rebalancing increases the likelihood of rapid directional continuation into market close.