---
title: "Get Volatility Index"
method: GET
path: "/api/market/volatility"
tags: ["Market Data"]
---

# Get Volatility Index

`GET /api/market/volatility`

## Request

- Base URL: `https://api.zerogex.io` (the document declares no server; this is the origin it was published from)
- URL: `https://api.zerogex.io/api/market/volatility`
- Auth: HTTP bearer

Returns volatility-index metrics as two scored dimensions, for either
the CBOE S&P 500 Volatility Index (``ticker=VIX``, default) or the CBOE
Nasdaq-100 Volatility Index (``ticker=VXN``).

**Level** — *where is the index right now?*
Maps the current reading to a 0–10 log scale anchored to historical
percentiles:
- `0–2`  → Subdued  (~10–15, historically quiet)
- `2–4`  → Low      (~15–19, below-average vol)
- `4–6`  → Moderate (~19–27, near long-run average)
- `6–8`  → Elevated (~27–38, above-average fear)
- `8–10` → Extreme  (~38+, crisis-level fear)

**Momentum** — *which direction and how fast is the index moving?*
Weighted composite rate-of-change across five time scales (5 min through
2 hrs), normalised against realised per-bar volatility of the index.

**Data source** — reads the rolling 5-min bar window maintained by the
per-ticker streaming ingester (VIX → ``vix_bars``, VXN → ``vxn_bars``).

## Query parameters

- `ticker` 'VIX' | 'VXN': Volatility index to score: 'VIX' ($VIX.X) or 'VXN' ($VXN.X).

## Response `200`

Successful Response

- VolatilityIndexResponse
  - `timestamp` string, date-time, required: Timestamp of the latest bar (ET)
  - `index` number, required: Current index close (e.g. $VIX.X or $VXN.X)
  - `level` number, required: Index level mapped to 0–10 (log scale). 0 = ultra-calm (~10), 5 = ~25, 10 = extreme fear (~50+).
  - `level_label` string, required: Human-readable label: Subdued / Low / Moderate / Elevated / Extreme
  - `momentum` number, required: Index rate-of-change mapped to 0–10 (±4σ range). 0 = collapsing, 5 = stable, 10 = surging.
  - `momentum_label` string, required: Human-readable label: Collapsing / Easing / Stable / Rising / Surging
  - `cache_bars` integer, required: 5-min bars used from the per-ticker bars table for this response
  - `latest_bars` VolatilityBar[]: Most-recent 10 bars for debugging / charting
    - `timestamp` string, date-time, required
    - `close` number, required

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/zerogex/apis/zerogex-api.md) · [All operations](https://skmtc.dev/zerogex/apis/zerogex-api/llms.txt) · [OpenAPI document](https://skmtc.dev/zerogex/apis/zerogex-api/revisions/753b26bf0592?raw)