---
title: "25Δ / 10Δ skew + 25Δ butterfly per expiry"
method: GET
path: "/options/iv/skew"
tags: ["Options"]
---

# 25Δ / 10Δ skew + 25Δ butterfly per expiry

`GET /options/iv/skew`

## Request

- Base URL: `https://docs.backquant.com/v2`
- URL: `https://docs.backquant.com/v2/options/iv/skew`
- Auth: API key in header `X-API-Key`

Delta-interpolated risk-reversal and butterfly per active expiry. `skew_25d` = 25Δ put IV − 25Δ call IV (positive = put premium, fear bid); `butterfly_25d` = (25Δ put IV + 25Δ call IV) / 2 − ATM IV (smile curvature / wing pricing). Computed from real delta-bracketed options, not strike proxies.

## Query parameters

- `symbol` 'BTCUSDT' | 'ETHUSDT' | 'SOLUSDT' | 'HYPEUSDT': Trading symbol: BTCUSDT, ETHUSDT, SOLUSDT, or HYPEUSDT.

## Headers

- `X-API-Key` string, nullable

## Response `200`

Successful Response

- IvSkewResponse
  - `success` true
  - `data` IvSkewData, required
    - `expiries` IvSkewExpiryRow[], nullable
      - `expiry` string, required
      - `expiry_label` string, nullable
      - `dte` integer, nullable
      - `atm_iv` number, nullable
      - `put_25d_iv` number, nullable
      - `call_25d_iv` number, nullable
      - `skew_25d` number, nullable
      - `put_10d_iv` number, nullable
      - `call_10d_iv` number, nullable
      - `skew_10d` number, nullable
      - `butterfly_25d` number, nullable
    - `spot_price` number, nullable
    - `ts` string, nullable
  - `meta` V2Meta, required: The meta block returned alongside every v2 response. Every field after `version`/`timestamp` is optional because endpoints attach different combinations — e.g. `/v2/status` skips `symbol`, the chain endpoint sets `extra.filter_hash`, etc. Listing them here means SDKs get a typed accessor for each instead of a generic `meta: dict`.
    - `version` '2.0', required: API version tag.
    - `timestamp` string, required: ISO 8601 wall-clock when the response was built.
    - `request_id` string, nullable: X-Request-ID for tracing across logs / Sentry.
    - `symbol` string, nullable: Symbol the response is about, if applicable.
    - `spot_price` number, nullable: Current spot price for the symbol.
    - `computed_at` string, nullable: ISO 8601 of when the underlying cache value was last written.
    - `freshness_seconds` number, nullable: `now - computed_at` in seconds; useful for staleness alarms.
    - `source` string[], nullable: Upstream venue list the data flowed through.
    - `exchanges_filtered` string[], nullable: Echo of the `?exchanges=` filter when one was applied.
    - `rate_limit` object, nullable: `{limit, remaining, reset}` echo of the rate-limit headers.
    - `extra` object, nullable: Open dict for endpoint-specific metadata (filter_hash, etc.).

## Other responses

- `401`: Invalid or missing API key
- `404`: Not Found
- `422`: Validation error on query parameters
- `429`: Rate limit exceeded

---

[API](https://skmtc.dev/backquant/apis/backquant-api-v2.md) · [All operations](https://skmtc.dev/backquant/apis/backquant-api-v2/llms.txt) · [OpenAPI document](https://skmtc.dev/backquant/apis/backquant-api-v2/revisions/3c1c96b3cc24?raw)