Trading endpoints

Purchase contracts. The loginid parameter removed, buy field validation relaxed, and buy object now required in response.

Cancel an active contract. The loginid parameter removed, cancel object now required in response, and all response fields now required.

Update contract parameters like take profit and stop loss. The loginid parameter removed, response object now required, and new display_order_amount field added.

Get contract update history. The loginid parameter removed, response field now required, and array items have required fields.

Get contract pricing. Symbol renamed to underlying_symbol, multiple parameters removed, response proposal now required with only id guaranteed, field types changed.

Get open contract details. The loginid parameter removed, numeric field types changed to string | number, and deprecated display fields removed.

Sell an active contract. The loginid parameter removed, price validation added, and sell response object with all fields now required.