Dealer Hedging Estimate

Q: How do dealers hedge?

When dealers sell options, they delta-hedge by trading shares. As the stock moves, gamma changes their delta, requiring rebalancing. This creates predictable flow.

Q: How many shares per 1% move?

For SPY, dealers may trade tens of millions of shares per 1% move — a significant fraction of daily volume.

Q: Why does Dealer Hedging matter for trading?

Dealer hedging quantifies the non-discretionary share flow dealers push through the tape for every 1% spot move. In liquid names it can exceed 5% of average daily volume, making it one of the largest flow categories in US equity markets. Traders use it to estimate how much intraday volatility is dealer-driven versus news-driven.

Q: When is Dealer Hedging good versus bad for a trader?

High hedging in positive gamma is good for premium sellers — dealers actively defend ranges. High hedging in negative gamma is dangerous for short-vol strategies — amplification goes against you. Low hedging in any regime means dealer flow is ignorable; trade direction on pure discretionary read.

Canonical definition, formula, interpretation, and API reference.

Definition

Estimated shares dealers must buy/sell to re-hedge for a given spot move. Quantifies the mechanical buying/selling pressure from delta hedging.

Formula

Hedging = Net GEX x dSpot / Spot

Approximated from aggregate gamma exposure times the percentage spot move.

Inputs

net GEXspot pricemove magnitude

Output

dealer_shares_to_tradedirectionnotional_usd

Interpretation

Positive gamma: dealers buy dips, sell rallies — dampening
Negative gamma: dealers sell dips, buy rallies — amplifying
Quantifies HOW MUCH mechanical flow each move triggers

API Reference

Endpoint

GET /v1/exposure/summary/{symbol}

Tier

Growth+

Response field

hedging_estimate.spot_down_1pct, spot_up_1pct

Why Dealer Hedging Matters for Trading

TL;DR

Dealer hedging tells you how many shares must change hands for every 1% spot move, purely to keep dealers delta-neutral. Big number = big intraday vol.

What it measures: Estimated share volume dealers must buy or sell per 1% underlying move to maintain a neutral book, derived from chain-wide gamma.
What it signals: The magnitude of non-discretionary order flow available to hit the tape. Higher means more amplification or damping, depending on regime.
Why we measure it: Volume matters. A regime call without size context is incomplete — high-dealer-hedging names behave very differently from low-hedging ones.
Who uses it: Institutional traders sizing orders, HFT / market-making desks, and anyone forecasting intraday volatility.

How to read Dealer Hedging

High hedging in positive gamma

Large dampening effect
Ranges hold with conviction
Walls very effective
Low realised vol

Good for: premium selling, tight ranges

High hedging in negative gamma

Large amplification effect
Small news = large moves
Walls break violently
High realised vol

Bad for: short vol — good for: long straddles

Low hedging (any regime)

Dealer flow is background noise
Price driven by discretionary flow
Ignore regime for strategy
Normal quiet-market reading

Low influence

Rules of thumb

Normalise by ADV. A 2M-share hedging number on a 100M-ADV name is tiny; on a 5M-ADV name it dominates. Express as % of ADV.
Combine with GEX sign. Direction of flow matters as much as size.
Peaks at OPEX. Share count balloons Thu/Fri of expiry week as gamma peaks.
Skip single stocks with thin options. Dealer flow is only meaningful when options volume is a significant share of equity volume.
High hedging + high dealer flow risk = danger. Non-trivial flow moving against you = size down.