On September 27th 2018,  we made the following updates to our trading engine. These changes may affect the way you do margin trading.

Funds used in spot positions on margin are now withheld.

• This will prevent traders from converting their margin collateral into a non-collateral currency (which could cause a liquidation).
• This will also prevent margin collateral from being converted into other collateral currencies.
• Collateral withheld per position is approximately the cost of the position divided by the leverage used, and then adjusted by the current profit/loss of the position.

Calculations for available margin have been updated.

• Profit/loss and open orders are now taken into account when placing a new order.
• Margin orders can no longer be placed using margin that is also being used in a different margin order. Previously, these orders would fail upon being triggered. Now the orders fail at creation.
• Buy-side and sell-side margin withholdings are not withheld in the opposite direction, up to the point of the original order. For example, if you have a 5 BTCUSD sell order that maxes out your margin, you can still place a 5 BTCUSD buy order (but not a 6 BTCUSD buy).