Option smile

IV-by-strike for a single expiration on the latest snapshot. Both option types returned, ordered by strike. Designed for direct plotting (x = strike, y = mark_iv) with optional bid/ask brackets.

The endpoint is a focused projection of Option chain — same underlying data, narrower column set, server-side filtered to non-zero IV.

SQL API

The smile shape comes from the same api.option_chains table:

WITH (
  SELECT max(timestamp)
  FROM api.option_chains
  WHERE exchange = 'deribit' AND underlying_asset = 'BTC'
) AS latest_ts
SELECT strike, option_type, mark_iv, bid_iv, ask_iv, delta, underlying_price
FROM api.option_chains
WHERE exchange = 'deribit'
  AND underlying_asset = 'BTC'
  AND toDate(expiration) = toDate('2026-06-26')
  AND timestamp = latest_ts
  AND mark_iv != 0
ORDER BY strike, option_type

Plot the result as a scatter / line over (strike, mark_iv) to see the smile. For an OTM-only wing curve, filter to option_type = 'C' AND strike > underlying_price (calls above spot) and option_type = 'P' AND strike < underlying_price (puts below spot).

Cross-expiration vol surface

To build a vol surface, query each expiration in turn (or join with dte in the result):

WITH (
  SELECT max(timestamp)
  FROM api.option_chains
  WHERE exchange = 'deribit' AND underlying_asset = 'BTC'
) AS latest_ts
SELECT
  toDate(expiration)                                AS expiry,
  strike / toFloat64(underlying_price)              AS moneyness,
  mark_iv                                           AS iv,
  toUInt32(date_diff('day', timestamp, expiration)) AS dte
FROM api.option_chains
WHERE exchange = 'deribit'
  AND underlying_asset = 'BTC'
  AND mark_iv != 0
  AND timestamp = latest_ts
ORDER BY expiry, moneyness

REST API

Get Volatility Smile

get

IV-by-strike for a single expiration on the latest snapshot. Both option types (C/P) returned, ordered by strike. Designed for direct plotting (x=strike, y=mark_iv).

Authorizations

x-api-keystringRequired

Required for /ohlcv and /trade endpoints. Pass your API key in the x-api-key header. Public /market/* endpoints do not require authentication.

Query parameters

exchangestring · enumRequired

Exchange — one of deribit, binance, okx, bybit.

Example: deribitPossible values:

underlying_assetstringRequired

Underlying coin (e.g. BTC).

Example: BTC

expirationstring · dateRequired

Expiry date, ISO (YYYY-MM-DD). Required.

Example: 2026-06-26

Responses

200

OK

application/json

strikenumber · decimalOptional

Strike price

option_typestring · enumOptional

Call or Put

Possible values:

mark_ivnumber · decimalOptional

Mark implied volatility (annualized %)

bid_ivnumber · decimalOptional

Bid IV

ask_ivnumber · decimalOptional

Ask IV

deltanumber · decimalOptional

Delta

underlying_pricenumber · decimalOptional

Spot/index price of the underlying at snapshot time

dteintegerOptional

Days-to-expiry

get/option/smile

GET /option/smile?exchange=deribit&underlying_asset=BTC&expiration=2026-06-26 HTTP/1.1
Host: api.koinju.io
x-api-key: YOUR_API_KEY
Accept: */*

200

OK

[
  {
    "strike": 1,
    "option_type": "C",
    "mark_iv": 1,
    "bid_iv": 1,
    "ask_iv": 1,
    "delta": 1,
    "underlying_price": 1,
    "dte": 1
  }
]