Is a large DEX bullish or bearish?

Neither by itself. It describes the delta embedded in open option positions under an assumption about who holds them. Whether that delta is already hedged, and how the hedge will be adjusted, depends on gamma, charm and vanna and on the actual positions, which are not public.

How is DEX different from GEX?

DEX is the delta of the book now; GEX is how fast that delta changes when the underlying moves. A book can have a large DEX and small GEX (deep in-the-money options) or the reverse (at-the-money options near expiry).

Delta exposure (DEX)

Delta exposure (DEX) aggregates the delta of all open option contracts on an underlying, each scaled by open interest and the contract multiplier and signed by a positioning assumption, into a share-equivalent or dollar figure. It estimates how much underlying the modelled option book represents, not the hedge actually held against it.

Senzoukria · Glossary · Updated September 2026

At a glance

Formula: DEX = Σ sign × OI × Δ × multiplier (shares); × spot for dollars
Inputs: Open interest, delta per leg, positioning convention
Changes intraday through: Spot (gamma), time (charm), implied volatility (vanna)

Definition

Each open option contract carries a delta: the share-equivalent exposure of one unit. Multiplying by open interest and the contract multiplier gives the delta of all outstanding contracts of that series, seen from the holders' side. A DEX model then assigns a sign to each leg according to who is assumed to hold it and sums across strikes and expiries. Expressed in shares, the result says how many units of underlying would offset the modelled book; multiplied by spot, it becomes dollars.

Worked example

Suppose a chain has 1,000 open calls with delta 0.50 and 2,000 open puts with delta −0.30, multiplier 100. From the holders' side, the calls carry +50,000 share-equivalents and the puts −60,000. Under a convention that counts calls with a plus sign and puts with a minus sign, as a dealer long the calls and short the puts would hold them, DEX = 50,000 − (−60,000) = +110,000 shares, about 55 million dollars with the underlying at 500.

What it is and is not

It is the delta of the option book under a positioning assumption. It is not the dealer's net position, because dealers hedge: a fully hedged book has zero net delta whatever its DEX.
Open interest is published once a day, so intraday changes in DEX come from deltas moving with spot, time and implied volatility, not from new positions.
Changes in DEX are more informative than its level: a rise in modelled option delta implies, under the assumption, a hedge that must be adjusted.
Different conventions produce different signs; compare DEX across tools only when their convention is stated.

In Senzoukria

The GEX overview shows a Total DEX tile in shares, and the per-strike data carries a net DEX. The app adds OI × delta × 100 for each call and subtracts OI × delta × 100 for each put, the same call-plus, put-minus convention as its gamma figures. Because put deltas are negative, both sides contribute positive share-equivalents under this convention, so the tile is read by its size and its changes rather than by its sign. When no leg carries both a delta and non-zero open interest, the tile states that the value is not in the chain instead of printing zero. The dealer-positioning switch of the Calculation assumptions panel recomputes the key levels, not this tile.

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Frequently asked questions

Is a large DEX bullish or bearish?: Neither by itself. It describes the delta embedded in open option positions under an assumption about who holds them. Whether that delta is already hedged, and how the hedge will be adjusted, depends on gamma, charm and vanna and on the actual positions, which are not public.
How is DEX different from GEX?: DEX is the delta of the book now; GEX is how fast that delta changes when the underlying moves. A book can have a large DEX and small GEX (deep in-the-money options) or the reverse (at-the-money options near expiry).

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