# Bullflow End-of-Day GEX (Gamma Exposure) Data

> Bullflow End-of-Day GEX (Gamma Exposure) Data is a paid API for AI agents from api.bullflow.io, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-29).

Returns end-of-day gamma exposure (GEX) by strike and expiration for a given ticker and trading date, using closing open interest data.

## Facts

- Endpoint: GET https://api.bullflow.io/v1/data/eodGex?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bullflow-end-of-day-gex-gamma-exposure-data-d316954a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_idjZTVGi_naQddvBuaYtD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability bullflow-end-of-day-gex-gamma-exposure-data-d316954a
```

Example prompt: Pull the end-of-day gamma exposure breakdown for SPY for October 14, 2026 — I want to see the call GEX, put GEX, and net GEX by strike and expiration so I can find the gamma wall.

## When to prefer this

Use this endpoint when you need end-of-day gamma exposure (GEX) data broken down by strike and expiration for a specific ticker and date. It is ideal for identifying gamma walls, dealer hedging zones, and net gamma concentration for quantitative options analysis or pre-market preparation. Prefer this over real-time flow endpoints when you want the settled, closing-position snapshot rather than intraday activity.

## Known failure modes

- HTTP 404 if the requested date has no available historical GEX data for the ticker
- Missing or invalid ticker returns an error
- Date format not matching YYYY-MM-DD pattern will fail schema validation
- Requesting a future date may return no data or an error
- Rate limiting or payment failure may block the response

## How this service works

Bullflow.io is a real-time unusual options flow and dark pool tracker with advanced tools to view, filter, and analyze market activity as it happens.

## Output

A JSON object containing the ticker, spot price at close, snapshot timestamp, the open interest date (prior session), and an array of strikes each with call GEX, put GEX, and net GEX values expressed in USD per 1% underlying move, broken out by expiration date. All times are in America/New_York timezone.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "ticker"
     ],
     "properties": {
      "date": {
       "type": "string",
       "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
       "description": "Trading date in YYYY-MM-DD format."
      },
      "ticker": {
       "type": "string",
       "examples": [
        "SPY"
       ],
       "description": "Underlying stock, ETF, or supported index ticker."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "required": [
      "ticker",
      "spot_price",
      "as_of",
      "strikes",
      "date",
      "open_interest_date",
      "timezone"
     ],
     "properties": {
      "date": {
       "type": "string",
       "description": "Selected trading date in YYYY-MM-DD format. Historical availability varies by ticker and session; unavailable history returns HTTP 404."
      },
      "as_of": {
       "type": "string",
       "description": "Timestamp of the closing underlying price used in the snapshot, in UTC."
      },
      "ticker": {
       "type": "string"
      },
      "strikes": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "expiration",
         "strike",
         "call_gex",
         "put_gex",
         "net_gex"
        ],
        "properties": {
         "strike": {
          "type": "number",
          "description": "Amount in US dollars."
         },
         "net_gex": {
          "type": "number"
         },
         "put_gex": {
          "type": "number"
         },
         "call_gex": {
          "type": "number"
         },
         "expiration": {
          "type": "string",
          "description": "Option expiration date in YYYYMMDD format."
         }
        }
       },
       "description": "Call, put, and net GEX in USD per 1% underlying move, by strike and expiration."
      },
      "timezone
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "date": "2026-10-14",
  "as_of": "2026-10-14T20:00:00Z",
  "ticker": "SPY",
  "strikes": [
   {
    "strike": 600,
    "net_gex": 100000,
    "put_gex": -100000,
    "call_gex": 200000,
    "expiration": "20261016"
   }
  ],
  "timezone": "America/New_York",
  "spot_price": 600,
  "open_interest_date": "2026-10-13"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bullflow-end-of-day-gex-gamma-exposure-data-d316954a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.bullflow.io](https://www.zero.xyz/host/api.bullflow.io/llms.txt)