Exchange Sharding

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Overview

In order to scale capacity, Kalshi will be splitting trading across multiple matching engines. Exchange instances will correspond to a specific category (e.g. “crypto” exchange, a “combos” exchange). Kalshi plans to add shards incrementally to maintain a healthy balance of traffic.

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Timeline

Kalshi will migrate combos from the “default” exchange instance to shard 1, followed by crypto and selected sports series.

• August 6, 2026: intra-exchange instance transfers enabled to exchange index 1.
• August 10, 2026: KXMVECROSSCATEGORY-SHARD1-R multivariate event collection created with support for all combos.
• August 17, 2026: combos created over legacy collections KXMVESPORTSMULTIGAMEEXTENDED-R, KXMVECROSSCATEGORY-R will be created on shard 1.
• August 24, 2026: new crypto events will be created on shard 2, and new tennis and baseball events will be created on shard 3.

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Balance Management

Kalshi’s collateralization checks will continue to run within the matching engine. Programmatic traders must preallocate collateral on a given exchange shard before order placement. Funding Overview

• Account transfers can be made through the Intra Account Transfer API.
• Manual transfers are also available through the Kalshi UI.
• Get Balance provides a breakdown of account balances across exchange indexes.

Subaccounts Overview

• To fund a subaccount on a new exchange instance, first transfer user-level funds to the desired exchange instance.
• Next, use Create Subaccount with the exchange_index parameter to provision the subaccount on the new instance.
• Then, use Transfer Between Subaccounts with the exchange_index parameter to transfer funds from the primary account to the subaccount on that instance.
• Get All Subaccount Balances provides a breakdown of subaccount balances for each (exchange_index, subaccount) pair.

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Order routing

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Market Data

• A new field exchange_index is provided on GET /markets, GET /events, and via the market and event lifecycle WebSocket streams for newly created events and markets.
• Market ticker formats are unaffected by exchange sharding. The exchange_index field is the authoritative source of truth.

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REST

The exchange_index parameter is available on a per-endpoint basis.

• If omitted: defaults to 0.
• Else if -1: routes to the target exchange for the provided market ticker.
• Else if >= 0: routes directly to the target exchange.

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FIX

The ExDestination parameter (FIX Tag 100) is available on a per-message basis.

• If omitted: defaults to 0.
• Else if -1: routes to the target exchange for the provided Symbol (FIX Tag 55).
• Else if >= 0: routes directly to the target exchange.

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Upcoming Series Shard Assignments

The following assignments determine the shard where new events will be created. Shard 0 is the catch-all for all categories and tags not listed below.

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FAQ

• All child markets of an event will live on the same exchange instance.
• There is currently no plan to migrate any live market to a new exchange instance.
• Providing ExDestination / exchange_index is unnecessary for all RFQ operations, including FIX QuoteRequest (35=R), Quote (35=S), and AcceptQuote (35=UA), which are routed internally by Kalshi.
• Automatic routing will incur an additional latency cost.
• Subaccount balances are local to a specific exchange instance.
• Order groups do not function across exchange instances.
• KXMVECROSSCATEGORY-SHARD1-R is live in demo for testing.