Suppose that you enter into a short futures contract on copper when the futures price is $6,012 per ton. The size of the contract is 8,000 tonnes. The initial margin is $100,000 and the maintenance margin is $80,000.

a) What change in the futures price will lead to a margin call? (4 marks)

b) What price change will allow you to withdraw $10,000 from the margin account? (4 marks)