Forward contracts: Usually closed out, private contract between 2 parties, non-standard contract, 1 specified delivery date, settled at end of contract, some credit risk
Futures contracts: Exchange traded, standard contract, range of delivery dates, settled daily, virtually no credit risk
Arbitrage profit is $30 if the spot price of gold is $1,400, the 1-year forward price of gold is $1,500, and the 1-year US$ interest rate is 5% per annum
Arbitrage profit is $70 if the spot price of gold is $1,400, the 1-year forward price of gold is $1,400, and the 1-year US$ interest rate is 5% per annum