"Assume zero rates and no other costs or benefits, gold spot is $$1850,$ and a broker is quoting you a $1-$year forward price on gold at $$2000.$ You can lock in an arbitrage

profit by

$("\text{'}$long$"\text{'}"$ or $"\text{'}$short$"\text{'})$ the forward at K$=2000$ and

$("\text{'}"$buy$"\text{'}"$ or $"\text{'}$sell$"\text{'})$ the gold on the spot market with bank financing

$($either borrow from bank or save money to bank$)$ today. This will lock in a profit of

dollars $($ use integer$)$ at $1-$year expiry per each unit $("\text{'}$share$"\text{'}")$ of

gold you trade."