---
title: "Decrease Order (V2)"
method: POST
path: "/portfolio/events/orders/{order_id}/decrease"
tags: ["orders"]
---

# Decrease Order (V2)

`POST /portfolio/events/orders/{order_id}/decrease`

Endpoint for decreasing the remaining count of an existing event-market order using the V2 request/response shape. Exactly one of `reduce_by` or `reduce_to` must be provided.

## Path parameters

- `order_id` string, required

## Query parameters

- `subaccount` integer

## Request body

- DecreaseOrderV2Request
  - `reduce_by` string — Fixed-point contract count string (2 decimals, e.g., "10.00"; referred to as "fp" in field names). Requests accept 0-2 decimal places (e.g., "10", "10.0", "10.00"); responses always emit 2 decimals. Fractional contract values (e.g., "2.50") are supported; the minimum granularity is 0.01 contracts.
  - `reduce_to` string — Fixed-point contract count string (2 decimals, e.g., "10.00"; referred to as "fp" in field names). Requests accept 0-2 decimal places (e.g., "10", "10.0", "10.00"); responses always emit 2 decimals. Fractional contract values (e.g., "2.50") are supported; the minimum granularity is 0.01 contracts.
  - `exchange_index` integer — Identifier for an exchange shard. Defaults to 0 if unspecified.
  - `market_ticker` string — Market ticker. Required when exchange_index is -1 (auto).

## Response `200`

Order decreased successfully

- DecreaseOrderV2Response
  - `order_id` string, required
  - `client_order_id` string
  - `remaining_count` string, required — Fixed-point contract count string (2 decimals, e.g., "10.00"; referred to as "fp" in field names). Requests accept 0-2 decimal places (e.g., "10", "10.0", "10.00"); responses always emit 2 decimals. Fractional contract values (e.g., "2.50") are supported; the minimum granularity is 0.01 contracts.
  - `ts_ms` integer, required — Matching engine timestamp at which the decrease was processed, as Unix epoch milliseconds.

## Other responses

- `400` — Bad request - invalid input
- `401` — Unauthorized - authentication required
- `404` — Resource not found
- `500` — Internal server error

---

[API](https://skmtc.net/kalshi/apis/kalshi-trade-api-manual-endpoints.md) · [All operations](https://skmtc.net/kalshi/apis/kalshi-trade-api-manual-endpoints/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/kalshi/kalshi-trade-api-manual-endpoints/revisions/6e6402bf667d/schema)