New to vanna exposure? Vanna & Charm Guide explains how second-order Greeks drive dealer flows.

Endpoint

GET /v1/exposure/vex/{symbol}

Auth required (X-Api-Key) Rate Limited: Yes Basic+

Parameters

Name	In	Required	Default	Description
`symbol`	path	yes	-	Underlying symbol
`expiration`	query	no	`all`	Filter by expiry date `yyyy-MM-dd`, or `0dte` for same-day only

curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/exposure/vex/SPY"

import requests

resp = requests.get(
    "https://lab.flashalpha.com/v1/exposure/vex/SPY",
    headers={"X-Api-Key": "YOUR_API_KEY"}
)
data = resp.json()
print(f"Net VEX: ${data['net_vex']:,.0f}")
print(f"Interpretation: {data['vex_interpretation']}")

const resp = await fetch(
  "https://lab.flashalpha.com/v1/exposure/vex/SPY",
  { headers: { "X-Api-Key": "YOUR_API_KEY" } }
);
const data = await resp.json();
console.log(`Net VEX: $${data.net_vex.toLocaleString()}`);
console.log(`Interpretation: ${data.vex_interpretation}`);

API Key

Response

{
  "symbol": "SPY",
  "underlying_price": 597.505,
  "as_of": "2026-02-28T16:30:45Z",
  "net_vex": 1200000000,
  "vex_interpretation": "Positive vanna  -  benefits from vol compression",
  "strikes": [
    {
      "strike": 575.0,
      "call_vex": 2300000,
      "put_vex": 1800000,
      "net_vex": 4100000
    }
  ]
}

Key Response Fields

Field	Type	Description
`symbol`	string	Underlying symbol
`underlying_price`	number	Current price of underlying
`as_of`	string	ISO 8601 timestamp
`net_vex`	number	Aggregate net vanna exposure in dollars
`vex_interpretation`	string	Plain-English directional interpretation of vanna exposure
`strikes`	array	Per-strike breakdown
`strikes[].strike`	number	Strike price
`strikes[].call_vex`	number	Call vanna exposure at this strike
`strikes[].put_vex`	number	Put vanna exposure at this strike
`strikes[].net_vex`	number	Net (call + put) vanna exposure

What Is Vanna Exposure?

Vanna exposure (VEX) measures how much dealer delta changes in response to a shift in implied volatility (dDelta/dVol). When IV drops (vol crush), positive vanna means dealers gain delta and must sell shares to hedge - creating a tailwind for prices. When IV rises, the reverse happens. VEX is critical around events like FOMC, earnings, and VIX expiration, where implied volatility can move sharply. The endpoint includes an interpretation field that summarizes the directional implication in plain English.

Common Use Cases

Pre-event positioning - anticipate how an IV crush or spike after earnings/FOMC will trigger dealer hedging flows
Vol regime analysis - positive VEX in a declining-vol environment is a bullish signal (dealers buying the underlying)
VIX correlation trades - combine VEX with VIX levels to time entries around volatility mean-reversion
Portfolio hedging timing - use VEX to gauge when vol-driven flows will push the underlying in your favor
Multi-greek dashboards - pair VEX with GEX and CHEX for a complete picture of second-order dealer flows

Vanna Exposure (VEX) API