# Volatility index
## SQL API
### `public_data.volatility_index`
Minute-resolution OHLC bars of the volatility index published by an exchange. Currently the primary source is **Deribit's DVOL** for `BTC` and `ETH` — a 30-day forward-looking implied-volatility index analogous to the VIX in traditional finance.
#### Columns
| Column | Type | Description |
| ----------- | ---------------------- | --------------------------------------------- |
| `exchange` | LowCardinality(String) | Exchange that publishes the index (`deribit`) |
| `market` | LowCardinality(String) | Underlying asset (`BTC`, `ETH`) |
| `timestamp` | DateTime64(9, 'UTC') | Bar timestamp |
| `open` | Decimal(76, 20) | Open value of the index for the bar |
| `high` | Decimal(76, 20) | High value |
| `low` | Decimal(76, 20) | Low value |
| `close` | Decimal(76, 20) | Close value |
The index is quoted in **annualised volatility percentage points**: a value of `55.21` means a 55.21% annualised IV.
#### Example: latest BTC and ETH DVOL
```sql
SELECT
timestamp,
market,
close
FROM public_data.volatility_index
WHERE exchange = 'deribit'
AND market IN ('BTC', 'ETH')
AND timestamp >= now() - INTERVAL 24 HOUR
ORDER BY timestamp DESC, market ASC
LIMIT 50
```
#### Example: 1-hour resampled DVOL
The raw bars are at 1-minute resolution. Aggregate to whatever interval you need:
```sql
SELECT
toStartOfHour(timestamp) AS hour,
market,
argMin(open, timestamp) AS open,
max(high) AS high,
min(low) AS low,
argMax(close, timestamp) AS close
FROM public_data.volatility_index
WHERE exchange = 'deribit'
AND market = 'BTC'
AND timestamp >= now() - INTERVAL 7 DAY
GROUP BY hour, market
ORDER BY hour ASC
```
#### Example: realised vs implied (DVOL) spread
Pair the index against realised vol from `api.ohlcv` to spot dislocations:
```sql
WITH dvol AS (
SELECT
toStartOfDay(timestamp) AS day,
avg(close) AS dvol_close
FROM public_data.volatility_index
WHERE exchange = 'deribit'
AND market = 'BTC'
AND timestamp >= now() - INTERVAL 30 DAY
GROUP BY day
),
returns AS (
SELECT
toStartOfDay(start) AS day,
toFloat64(close) AS close
FROM api.ohlcv(candle_duration_in_minutes = 1440)
WHERE exchange = 'binance'
AND market = 'BTC-USDT'
AND start >= now() - INTERVAL 31 DAY
),
realised AS (
SELECT
day,
100.0 * sqrt(365)
* stddevSamp(log(close / lagInFrame(close, 1) OVER (ORDER BY day))) AS rv30
FROM returns
)
SELECT
d.day,
d.dvol_close AS dvol,
r.rv30 AS realised_30d_annualised,
d.dvol_close - r.rv30 AS premium
FROM dvol d
LEFT JOIN realised r USING (day)
ORDER BY day ASC
```
A positive `premium` (DVOL > realised) is the typical state — option sellers earn the spread on average. Spikes in `realised` above `dvol` flag tail-risk events.
## REST API
## Get volatility index OHLC
> Returns OHLC (open / high / low / close) of an exchange's published\
> volatility index for a given underlying. Currently the primary\
> source is Deribit's DVOL (BTC and ETH).\
> \
> This endpoint is limited to 10000 records per request.
```json
{"openapi":"3.1.1","info":{"title":"Koinju Market Data API","version":"1.0.0"},"servers":[{"url":"https://api.koinju.io","description":"Koinju API Server"}],"security":[{"apiKeyAuth":[]}],"components":{"securitySchemes":{"apiKeyAuth":{"type":"apiKey","in":"header","name":"x-api-key","description":"Required for /ohlcv and /trade endpoints.\nPass your API key in the x-api-key header.\nPublic /market/* endpoints do not require authentication.\n"}}},"paths":{"/volatility-index":{"get":{"summary":"Get volatility index OHLC","description":"Returns OHLC (open / high / low / close) of an exchange's published\nvolatility index for a given underlying. Currently the primary\nsource is Deribit's DVOL (BTC and ETH).\n\nThis endpoint is limited to 10000 records per request.\n","tags":["market_data"],"parameters":[{"name":"exchange","in":"query","required":true,"description":"Exchange that publishes the index (e.g. `deribit`).","schema":{"type":"string"}},{"name":"market","in":"query","required":true,"description":"Underlying asset (e.g. `BTC`, `ETH`).","schema":{"type":"string"}},{"name":"start_datetime","in":"query","required":true,"description":"Window start in ISO 8601 (e.g. `2026-03-01T00:00:00Z`) or any\nformat parseable by `parseDateTime64BestEffort`.\n","schema":{"type":"string","format":"date-time"}},{"name":"end_datetime","in":"query","required":true,"description":"Window end in ISO 8601.","schema":{"type":"string","format":"date-time"}}],"responses":{"200":{"description":"OK","content":{"application/json":{"schema":{"type":"array","items":{"type":"object","properties":{"time":{"type":"string","format":"date-time","description":"Bar timestamp (UTC)"},"exchange":{"type":"string","description":"Exchange that publishes the index"},"market":{"type":"string","description":"Underlying asset"},"open":{"type":"number","format":"decimal","description":"Open value of the index for the bar"},"high":{"type":"number","format":"decimal","description":"High value"},"low":{"type":"number","format":"decimal","description":"Low value"},"close":{"type":"number","format":"decimal","description":"Close value"}}}}}}}}}}}}
```
---
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