Position Count Limit

The position count limit is a risk management feature that allows exchange operators to set a maximum number of positions that each account can hold simultaneously. It is an exchange-wide setting that applies uniformly to all trading accounts. When configured, it restricts the number of distinct instrument positions that any single account can hold at one time.

How Position Count Limit Works

Position Counting

The position count limit counts all of the following toward the limit:

• Active Positions: Any non-zero position on any instrument
• Unterminated Orders: All resting orders, including:
  • Limit orders in the order book
  • Stop orders waiting to be triggered
  • Contingent orders

This comprehensive counting ensures that even orders that haven't yet resulted in positions are accounted for in the limit.

Order Rejection Criteria

Orders on instruments where the account has no existing position or orders are rejected if the account is at the limit.

Allowed Operations

Even when at or over the position count limit, accounts can still:

• Trade Existing Positions: Place orders on instruments where the account already has a position or unterminated orders
• Close Positions: Use reduce-only or close orders to exit existing positions
• Modify Existing Orders: Amend or cancel existing orders

Closing Positions

When an account closes a position (reduces it to zero and has no unterminated orders on that instrument), the capacity is freed:

• The position count decreases by one
• The account can now open a position on a different instrument
• This allows accounts to rotate between instruments while respecting the limit

Limit Reduction

If the exchange operator reduces the position count limit downward, accounts that are already over the new limit are grandfathered:

• Existing Positions Protected: The account can continue trading its existing positions
• New Positions Blocked: The account cannot open positions on new instruments until it falls below the new limit
• Gradual Compliance: Accounts naturally come into compliance as they close positions

Liquidation Account Exception

The liquidation account can receive positions through the liquidation process even if such positions would cause it to exceed the position count limit.

Reference

API Endpoints

All position count limit endpoints are part of the Exchange-Wide Controls API and are accessible via the control gateway (port 8181).

Set Position Count Limit

Configure the maximum number of positions allowed per account across the entire exchange.

POST /ExchangeWideControls/PositionCountLimit?limit={count}

Parameters

Example

curl -X 'POST' \
  'http://control-gateway:8181/ExchangeWideControls/PositionCountLimit?limit=100' \
  -H 'accept: application/json' \
  -d ''

This sets the position count limit to 100 positions per account across the entire exchange.

Response

Returns confirmation of the position count limit configuration.

Get Position Count Limit

Retrieve the current position count limit setting.

GET /ExchangeWideControls/PositionCountLimit

Example

curl -X 'GET' \
  'http://control-gateway:8181/ExchangeWideControls/PositionCountLimit' \
  -H 'accept: application/json'

Response

Returns the current position count limit value, or indicates if no limit is set.

Delete Position Count Limit

Remove the position count limit, allowing accounts to hold unlimited positions.

DELETE /ExchangeWideControls/PositionCountLimit

Example

curl -X 'DELETE' \
  'http://control-gateway:8181/ExchangeWideControls/PositionCountLimit' \
  -H 'accept: application/json' \
  -d ''

Response

Returns confirmation that the position count limit has been removed.

Related Documentation

• See Liquidation Account for information about the liquidation account's special properties
• See Maintenance Margin for the overall liquidation workflow