An investor takes a long position in 1 March silver futures contract on August 22nd. The contract size is 5,000 ounces with a futures price today (i.e. settlement price) of US$ 19.40/oz. The initial margin requirement is US$10,000/contract with a maintenance margin of US$7,000/contract. The futures price (US$/oz) over the next 5 trading days (i.e. August 23rd and onwards) are: $19.20, $19.05, $18.95, $18.50 and $18.51.

For each day, track the daily gain (or loss), cumulative gain (or loss) and margin balance (US$). Was there a margin call (i.e. when the margin balance falls below the maintenance margin)? If there was a margin call, how much cash is immediately required to bring the balance back up to the initial margin of US$10,000/contract?