--- 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 on a /api/v1/* response envelope built through `helpers.response.sugra_response`, which is how routes are expected to answer. A route that assembles its own `meta` dict carries only the keys it writes itself, so an optional field below can be absent because this response has nothing to report OR because that route does not build its envelope here - the two are not distinguishable from the outside (API-43). - `endpoint` string, required — Requested endpoint path. - `data_time` string, required — ISO 8601 timestamp the data on this response is stamped with. It is the source's own timestamp whenever the source supplied one this API could read; when it did not, this field falls back to the value of `response_time` and `data_age_days` is omitted, so the PRESENCE of that field is the signal to read - with the one exception named in its own description, a route that substitutes its own current time for a source timestamp it never received. Usually UTC (`Z`), but a source stating its own numeric offset keeps it (2026-04-16T14:30:00+09:00) rather than being converted a second time. For a source that publishes by period this is the period's START (see `period`) and for one that publishes by calendar day it is that day's midnight - in neither case a moment at which anything was observed or released. - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced. - `provider` string, required — API name and version. - `data_age_days` number, nullable — Age of the data in days at the moment this response was produced, i.e. `response_time` minus `data_time`. Present ONLY when the timestamp this response is stamped with is a clock time that could be read as a real instant. It is ABSENT - never 0 - in every other case. Absent when no readable source timestamp was supplied, because `data_time` then repeats `response_time` and a zero age would assert that the data is current precisely where its true age is unknown. Absent when the source names a calendar day, a month, a quarter or a year (see `period`): the instant is then a boundary this API anchored at midnight, and time since a day or a quarter BEGAN is a different quantity from the age of the data - a daily series is out by up to a day, a quarterly one by up to a quarter. A midnight counts as such a boundary whichever zone it is stated in, and whether the source stated it or this API anchored it. The one case this field cannot see is a route that substitutes its own current time for a source timestamp it never received: the substituted value is a real, readable instant and is indistinguishable from one the source stated, so the age reads as roughly 0. The shared cache-and-fetch helper behind most routes stopped doing that (API-43), but the presence of this field is a statement about the timestamp the response carries, not a guarantee about the route that supplied it. Rounded to 0.001 day (86.4 seconds), so 0.0 is a real measured age anywhere within roughly +/-43 seconds and not a stand-in for unknown; a source stamping an instant in the future reports a negative value (-0.001 or less) rather than being clamped. Sources publish on very different cadences, so a non-zero age is normal, not an error. Preserve absence in client code: a generated client that materialises a missing optional number as its numeric default turns 'age unknown' back into 'age zero', which is the exact confusion this field exists to remove. - `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. - `stale_since` string, nullable — ISO 8601 UTC timestamp of the last good copy this response was served from. Present only when stale is true. - `period` string, nullable — Unit of observation, when the source publishes by period rather than by instant. `data_time` carries the period's START instant so it stays machine-readable; this field preserves what that instant used to mean, which the conversion would otherwise erase. Present only for such sources, and only when the source hands the API the label itself - a client that converts the period to its start instant before building the envelope loses the label, though not the age exclusion, which is decided by the instant. Note that `data_age_days` is omitted whenever this is present, because an age measured from a period start is not a freshness figure. - `notes` string, nullable — Data-quality caveat about THIS response - how old the underlying report is, a chokepoint AIS lower-bound, or that a source-reported `data_time` could not be read and the response time is shown instead. Distinct from `attribution`, which is a licensing obligation. Multiple caveats are joined with ' | '. Present only when there is one. ## 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. - `500` — This API answered a shape its own schema refuses. Typed body `error: response_shape_invalid`. Stays a 500 (WEB-28). Not an upstream failure. - `503` — Upstream source is temporarily unavailable. Retry after a short delay. ## Changes > 32 revisions in range; 1 not diffed. - **2026-09-13** `d2472ec2cf81` — 1 info - added the non-success response with the status `500` - **2026-09-09** `4f8853a61440` — 1 info - added the optional property `meta/stale_since` to the response with the `200` status - **2026-09-01** `328d061c12ca` — 3 info - added the optional property `meta/data_age_days` to the response with the `200` status - added the optional property `meta/notes` to the response with the `200` status - added the optional property `meta/period` to the response with the `200` status - **2026-08-08** `4c4530760ba1` — 1 info - endpoint added [Change history](https://skmtc.dev/sugra/apis/sugra-api/changes/api/v1/options/:symbol/iv-rank/get.md) --- [API](https://skmtc.dev/sugra/apis/sugra-api.md) · [All operations](https://skmtc.dev/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sugra/apis/sugra-api/revisions/d2472ec2cf81?raw)