## Wednesday, November 23, 2011

### Computing the Margin Balance for a Futures Account

CFA Level 1 - Derivatives

This concept will be better explained by using an example to compute the margin balance.
Let's start with a future's price of \$200. The initial margin requirement is \$10 and the maintenance margin is \$6. The trader buy five contracts and deposits \$50 (5 contacts * \$10)

Day 0 - The ending balance is \$50.
Day 1 - The price moves to \$199.50. The adjustment that needs to be made is -\$2.50 (200-199.5 * 5 contracts). The ending balance is now \$47.50 (\$50 - 2.50). Since this is above the maintained margin (\$30) no funds need to be added to the account.
Day 2 - The price moves down to \$195. The loss, based on five contracts, is \$22.50, so the account balance is \$25. This is below the maintenance margin. The trader will receive a margin call and will need to deposit \$25 into the account to bring it back up to the initial margin requirement.

This continues over the course of the trade until it is closed out. Please follow the following charts:

For a long position of five contracts, initial margin = \$5, maintenance margin =\$3

 Day Beginning Balance Funds Deposited Settlement Price Future Price Change Gain/Loss Ending Balance 0 0 25 50 1 25 0 49.6 -0.4 -2 23 2 23 0 48 -1.6 -8 15 3 15 0 48.5 0.5 2.5 17.5 4 17.5 0 49.25 0.75 3.75 21.25 5 21.25 0 51 1.75 8.75 30

For a short position of five contracts, initial margin = \$5, maintenance margin =\$3

 Day Beginning Balance Funds Deposited Settlement Price Future Price Change Gain/Loss Ending Balance 0 0 25 50 1 25 0 49.6 0.4 2 27 2 27 0 48 1.6 8 35 3 35 0 48.5 -0.5 -2.5 32.5 4 32.5 0 49.25 -0.75 -3.75 28.75 5 28.75 0 51 -1.75 -8.75 20