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Delta Exposure (DEX)

See where dealers hold directional risk. DEX reveals the strike-level delta that drives dealer hedging flows — positive DEX means dealers are long delta and will sell into rallies.

Delta exposure analysis shows directional dealer positioning by strike price. Enter any symbol to see net DEX, call/put walls, and how dealer delta shifts across strikes — updated with live options data.

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Symbol

Expiry

What can you do with DEX?

Directional Bias

DEX shows the net directional exposure of dealers. Positive net DEX means dealers are long delta and will sell into rallies, creating resistance. Negative net DEX means they buy dips, providing support.

Hedging Flows

Large DEX at a strike means significant dealer hedging activity. These strikes become magnets for price as dealers continuously adjust their directional exposure around them.

Market Maker Positioning

Track how delta shifts across strikes to spot accumulation. When DEX concentrates at specific strikes, it signals where market makers have built significant directional positions.

Get this via API

curl

# Single expiry (free tier)
curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/exposure/dex/SPY?expiration=2026-03-07"

# All expirations (Growth+ tier)
curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/exposure/dex/SPY"

Python

import requests

r = requests.get(
    "https://lab.flashalpha.com/v1/exposure/dex/SPY",
    params={"expiration": "2026-03-07"},  # yyyy-MM-dd
    headers={"X-Api-Key": "YOUR_API_KEY"}
)
data = r.json()
print(f"Net DEX: {data['net_dex']}")

Full API docs → Try in playground →

Get DEX via API

Single-expiry DEX is included on the free Starter plan (5 requests/day). Full-chain DEX across all expirations available on Growth (1,000/day) and Pro (unlimited).

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How Delta Exposure Is Calculated

Delta exposure quantifies the directional risk dealers carry at each strike. For a single option contract:

$$\text{DEX}_i = \Delta_i \times OI_i \times 100$$

Where:

$\Delta_i$ is the option's delta (first derivative of price with respect to underlying)
$OI_i$ is the open interest at that strike
The factor $100$ converts to shares per contract

Net DEX and the Dealer Convention

Dealers (market makers) are assumed to be short calls and long puts when retail buys them. Therefore:

$$\text{Net DEX} = \sum_{i} \text{DEX}_{i}^{\text{call}} + \sum_{i} \text{DEX}_{i}^{\text{put}}$$

Call delta is negative for dealers (they are short the call, so they must buy shares to hedge). Put delta is positive for dealers (they are long the put, which has negative delta, but their short position flips the sign). The sum captures the net directional exposure dealers must hedge.

Delta and the Black-Scholes Model

Under Black-Scholes, delta for a European call option is:

$$\Delta_{\text{call}} = N(d_1), \quad \Delta_{\text{put}} = N(d_1) - 1$$

Where $N(d_1)$ is the cumulative standard normal distribution evaluated at $d_1$. Delta ranges from 0 to 1 for calls and -1 to 0 for puts, representing the sensitivity of the option price to a $1 move in the underlying.

Why DEX Matters for Traders

While gamma exposure (GEX) shows how dealers must adjust hedges as price moves, delta exposure shows the current directional positioning. Large positive DEX at a strike means dealers hold significant long delta there and will sell shares as price approaches — creating natural resistance. Conversely, large negative DEX creates support as dealers buy to hedge.

DEX vs. GEX

Think of DEX as the "level" and GEX as the "rate of change." DEX tells you where dealers are directionally positioned right now. GEX tells you how quickly that positioning changes as the underlying moves. Together, they give a complete picture of the dealer hedging landscape.

Expiration Filtering

Near-dated options contribute concentrated DEX because their delta changes rapidly near the money. Our API supports filtering by expiration date so you can isolate 0DTE delta (which drives intraday hedging) from longer-dated positioning.

Limitations

Dealer assumption — DEX assumes dealers are short calls and long puts. In practice, some OI is inter-dealer or institutional hedging, which may have different sign conventions.
OI is T-1 — open interest is reported end-of-day by the OCC and reflects the previous session's close.
Not a crystal ball — DEX describes the mechanical hedging landscape, not future direction. Use it alongside price action, not as a standalone signal.