---
title: "IV rank + percentile of current ATM IV vs the snapshot history"
method: GET
path: "/api/v1/options/{symbol}/iv-rank"
tags: ["Options"]
---

# IV rank + percentile of current ATM IV vs the snapshot history

`GET /api/v1/options/{symbol}/iv-rank`

Ranks the CURRENT nearest-expiry ATM IV against the symbol's own dated snapshot history, so the consumer no longer has to accumulate and store that history client-side. ``window`` counts OBSERVATIONS (dated snapshots that yielded a gated ATM IV), default 252 - the annual convention - but the dated store retains 90 days, so ``observations_found`` discloses what the rank actually rested on. ``iv_rank`` is min-max scaled (null when the window's range is degenerate); ``iv_percentile`` is the share of observations at or below current. Fewer than 2 observations is a 503 ``insufficient_history``, never a rank fabricated from one point. Error codes match ``/snapshot``.

## Path parameters

- `symbol` string, required — Underlier ticker.

## Query parameters

- `window` integer — Window size in observations (30..504, default 252). Bounded in practice by the 90-day dated-snapshot retention; observations_found reports the reality.

## Response `200`

IV rank payload.

- EnvelopeOptionsIvRankPayload
  - `data` OptionsIvRankPayload, required — IV rank + percentile of the current nearest-expiry ATM IV against the symbol's own dated snapshot history.
    - `symbol` string, required — Underlier ticker.
    - `snapshot_date` string, required — Snapshot date of the CURRENT observation (YYYY-MM-DD).
    - `current_atm_iv` number, required — Nearest-expiry ATM IV of the latest snapshot (plausibility-gated) - the value being ranked.
    - `iv_rank` number, nullable — (current - min) / (max - min) * 100 over the window's observations, 0..100. Null when max == min (a degenerate range cannot be scaled - never fabricated as 0 or 100).
    - `iv_percentile` number, required — Share of window observations <= current, * 100. 50 = median of the window.
    - `window` integer, required — Requested window size in OBSERVATIONS (dated snapshots), not calendar days.
    - `observations_found` integer, required — Dated snapshots that actually yielded a gated ATM IV within the window. Bounded by the 90-day snapshot retention - a 252 observation request can never fill from a 90-day store, and this field says what it really rested on.
    - `retention_window_days` integer, required — The dated-snapshot retention bound (days) that caps how far back observations can exist.
    - `min_iv` number, required — Lowest windowed observation.
    - `max_iv` number, required — Highest windowed observation.
    - `first_observation_date` string, required — Oldest snapshot date that contributed an observation.
    - `last_observation_date` string, required — Newest snapshot date that contributed (the current one).
    - `methodology` string, required — How the daily observable is defined (nearest-expiry gated ATM IV) and how rank/percentile are computed.
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header. JSON body with a stable `code` distinguishing `missing_api_key` (no header sent) from `invalid_api_key` (header sent, key not accepted); any other 401 source carries the generic `unauthorized` with its detail as `reason`. Plus `hint`. `plan` is always null on 401 - an unauthenticated request has no plan; quota exhaustion is 429, not 401.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

[API](https://skmtc.net/sugra/apis/sugra-api.md) · [All operations](https://skmtc.net/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sugra/sugra-api/versions/a0c7dc18e21b/schema)