> ## Documentation Index
> Fetch the complete documentation index at: https://docs.amberdata.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Term Structures Constant

> This endpoint returns the term structure (for exchange listed expirations) with forward volatility calculations, for constant "daysToExpiration" maturities.



## OpenAPI

````yaml get /analytics/volatility/term-structures/forward-volatility/constant
openapi: 3.1.0
info:
  title: derivatives-api
  version: '2'
servers:
  - url: https://api.amberdata.com/markets/derivatives
security:
  - sec0: []
paths:
  /analytics/volatility/term-structures/forward-volatility/constant:
    get:
      summary: Term Structures Constant
      description: >-
        This endpoint returns the term structure (for exchange listed
        expirations) with forward volatility calculations, for constant
        "daysToExpiration" maturities.
      operationId: derivatives-volatility-term-structures-constant
      parameters:
        - name: exchange
          in: query
          description: >-
            **[Required]**  The exchange for which to retrieve the listed option
            level 1 quotes. 

            **[Examples]** ` deribit | okex | bybit`
          required: true
          schema:
            type: string
            default: deribit
        - name: currency
          in: query
          description: >-
            **[Required]** The underlying currency for which there are listed
            option instruments. 

            **[Examples]** ` BTC | SOL_USDC `  

            Note: inverse options have underlying currencies formatted as (BTC,
            ETH) while linear option currency formats include the stable coin in
            the same  (SOL_USDC)
          required: true
          schema:
            type: string
            default: BTC
        - name: timestamp
          in: query
          description: |-
            **[Required]** Payload only includes data for this timestamp. 
            **[Formats]** `seconds | milliseconds | iso8601`
            **[Examples]** `1578531600 | 1578531600000 | 2024-04-03T08:00:00`
          schema:
            type: string
            format: date-time
            default: '2024-04-12T00:00:00'
        - name: timeFormat
          in: query
          description: >-
            **[Optional]** Time format of the timestamps in the return payload.

            **[Defaults]** `milliseconds | ms* | iso | iso8601 | hr |
            human_readable`
          schema:
            type: string
      responses:
        '200':
          description: '200'
          content:
            application/json:
              examples:
                Result:
                  value:
                    status: 200
                    title: OK
                    description: Successful request
                    payload:
                      data:
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 1
                          atm: 48.35922628296513
                          fwdAtm: null
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 2
                          atm: 45.43736221438332
                          fwdAtm: 42.3142175080092
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 3
                          atm: 43.68325184564065
                          fwdAtm: 39.944607964365645
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 7
                          atm: 46.16990851827613
                          fwdAtm: 47.95034851977852
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 14
                          atm: 48.41110278679033
                          fwdAtm: 50.553034463624144
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 21
                          atm: 50.49107793015334
                          fwdAtm: 54.41302330858023
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 30
                          atm: 52.56344667911033
                          fwdAtm: 57.107257606586295
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 60
                          atm: 57.73201821661908
                          fwdAtm: 62.47444219791323
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 90
                          atm: 60.38590165981284
                          fwdAtm: 65.37124370147538
                        - timestamp: '2024-05-23T22:22:00.000Z'
                          exchange: deribit
                          currency: BTC
                          daysToExpiration: 180
                          atm: 65.50760799181039
                          fwdAtm: 70.25693055029386
                      metadata:
                        api-version: '2023-09-30'
              schema:
                type: object
                properties:
                  status:
                    type: integer
                    example: 200
                    default: 0
                  title:
                    type: string
                    example: OK
                  description:
                    type: string
                    example: Successful request
                  payload:
                    type: object
                    properties:
                      data:
                        type: array
                        items:
                          type: object
                          properties:
                            timestamp:
                              type: string
                              example: '2024-05-23T22:22:00.000Z'
                            exchange:
                              type: string
                              example: deribit
                            currency:
                              type: string
                              example: BTC
                            daysToExpiration:
                              type: integer
                              example: 1
                              default: 0
                            atm:
                              type: number
                              example: 48.35922628296513
                              default: 0
                            fwdAtm:
                              type: number
                              nullable: true
                              example: null
                              description: >-
                                Forward At The Money volatility (can be null for
                                short-term expirations)
                      metadata:
                        type: object
                        properties:
                          api-version:
                            type: string
                            example: '2023-09-30'
        '400':
          description: '400'
          content:
            application/json:
              examples:
                Result:
                  value: {}
              schema:
                type: object
                properties: {}
      deprecated: false
      security:
        - ApiKeyAuth: []
components:
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key

````