Dealer Delta Exposure (DEX)

Dealer delta exposure (DEX) is an estimate of the net directional exposure option dealers carry across the chain, built by aggregating each contract's delta weighted by open interest and signed by the estimated dealer side. Where gamma exposure describes how a dealer's hedge must change as price moves, DEX describes the size and direction of the hedge dealers are estimated to be carrying right now.

DEX is constructed the same way gamma exposure is, just with delta in place of gamma: for every strike and expiration, multiply the contract's delta by its open interest and a contract multiplier, apply a sign convention for which side dealers are presumed to hold, and sum the result across the chain. The output is a single figure - the estimated underlying-equivalent exposure sitting on dealer books at that moment.

DEX and GEX are companions, not substitutes. GEX describes the derivative - how fast the hedge must change as price moves - while DEX is closer to a snapshot of the hedge itself. A dealer book can carry a large net DEX with modest GEX, or the reverse, depending on how the position is distributed across strikes.

Because delta itself moves continuously with price (gamma), with time (charm), and with implied volatility (vanna), DEX is not static - it drifts through the session as those other Greeks act on the underlying positions. A large and growing net DEX in one direction is read as a rough gauge of how much directional hedging flow the dealer complex may still need to transact.

DEX carries the same estimation caveats as every other dealer-positioning metric: it depends on an assumption about which side of each contract dealers hold, and different methodologies can disagree on the exact figure. It is most useful read as a sign, a magnitude, and a trend over the session rather than as a literal share count.

A simple way to picture DEX: if the estimated aggregate dealer position across a chain totals a large amount of positive delta, that is roughly the underlying-equivalent exposure dealers would need to sell to return to a flat, fully hedged book. In practice that figure is rarely acted on all at once - it accumulates and unwinds continuously as new options trade, existing positions expire, and delta itself drifts with price, time, and volatility.

DEX is the whole-chain aggregate of a more granular underlying dataset: dealer-directional open interest (DDOI), which signs open interest strike by strike rather than summing it into one number. Reading DEX alongside its per-strike DDOI components shows not just how large the dealer hedge is in total, but exactly which strikes are contributing most to it, useful context when a small number of concentrated positions are driving most of an otherwise large aggregate figure.

DEX is also used to sanity-check other dealer-positioning reads: a chain showing large aggregate gamma exposure but a comparatively small or flat DEX suggests dealers are hedged with options spreads rather than carrying a large directional book, while a large DEX alongside modest gamma suggests a more directionally lopsided position that is less sensitive to near-term price changes. Reading the two figures together gives a fuller picture than either one alone.