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

# Calculate Incremental VaR

> Calculates how much portfolio VaR increases when adding a new position. This measures the absolute change in VaR from including the new asset, helping traders and portfolio managers assess the risk impact of new trades before execution. [Tier: PRO, Credits: 5]



## OpenAPI

````yaml api-specs/risk.json post /quantlib/risk/var/incremental
openapi: 3.1.0
info:
  title: FinceptQuantLib API - Risk Module
  description: >-
    Professional-grade risk management endpoints including Value at Risk (VaR),
    stress testing, copulas, extreme value theory (EVT), XVA calculations,
    sensitivities, and portfolio hedging. Part of the Pro Tier (5 credits per
    request).
  version: 3.0.0
  contact:
    name: Fincept API Support
    url: https://fincept.in
    email: support@fincept.in
servers:
  - url: https://api.fincept.in
    description: Fincept API Production Server
security:
  - APIKeyHeader: []
tags:
  - name: quantlib-risk
    description: Risk Management Module - Pro Tier (5 credits/request)
    x-displayName: Risk
paths:
  /quantlib/risk/var/incremental:
    post:
      tags:
        - quantlib-risk
      summary: Calculate Incremental VaR
      description: >-
        Calculates how much portfolio VaR increases when adding a new position.
        This measures the absolute change in VaR from including the new asset,
        helping traders and portfolio managers assess the risk impact of new
        trades before execution. [Tier: PRO, Credits: 5]
      operationId: incremental_var
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - portfolio_returns
                - new_position_returns
                - position_weight
              properties:
                portfolio_returns:
                  type: array
                  description: Historical returns of the existing portfolio
                  items:
                    type: number
                  example:
                    - 0.01
                    - -0.015
                    - 0.008
                new_position_returns:
                  type: array
                  description: Historical returns of the position to be added
                  items:
                    type: number
                  example:
                    - 0.02
                    - -0.025
                    - 0.012
                position_weight:
                  type: number
                  description: Weight of new position as fraction of total portfolio value
                  example: 0.1
                  minimum: 0
                  maximum: 1
                confidence:
                  type: number
                  example: 0.99
                  default: 0.99
                portfolio_value:
                  type: number
                  example: 1000000
                  default: 1000000
            example:
              portfolio_returns:
                - 0.008
                - -0.012
                - 0.015
                - -0.005
                - 0.009
              new_position_returns:
                - 0.025
                - -0.035
                - 0.018
                - -0.008
                - 0.02
              position_weight: 0.15
              confidence: 0.95
              portfolio_value: 5000000
      responses:
        '200':
          description: Successful incremental VaR calculation
          content:
            application/json:
              schema:
                type: object
                properties:
                  success:
                    type: boolean
                    example: true
                  data:
                    type: object
                    properties:
                      incremental_var:
                        type: number
                        description: Change in VaR from adding the new position
                        example: 15250
              example:
                success: true
                data:
                  incremental_var: 15250
        '401':
          $ref: '#/components/responses/UnauthorizedError'
        '402':
          $ref: '#/components/responses/InsufficientCreditsError'
        '422':
          $ref: '#/components/responses/ValidationError'
components:
  responses:
    UnauthorizedError:
      description: Authentication information is missing or invalid
      content:
        application/json:
          schema:
            type: object
            properties:
              detail:
                type: string
                example: Invalid API key
    InsufficientCreditsError:
      description: Insufficient API credits for this request
      content:
        application/json:
          schema:
            type: object
            properties:
              detail:
                type: string
                example: Insufficient credits. This endpoint requires 5 credits.
    ValidationError:
      description: Request validation error
      content:
        application/json:
          schema:
            type: object
            properties:
              detail:
                type: array
                items:
                  type: object
                  properties:
                    loc:
                      type: array
                      items:
                        type: string
                    msg:
                      type: string
                    type:
                      type: string
  securitySchemes:
    APIKeyHeader:
      type: apiKey
      in: header
      name: X-API-Key
      description: >-
        API key for authentication. Get your key at
        https://api.fincept.in/auth/register

````