a trader bought one june gold futures contract (size = 100 ounces) at $1,600/oz. the gold futures contracts are traded on the new york mercantile exchange. the initial margin requirement is $12,000. (ignore margin calls or maintenance margin in the following calculations.) (1) suppose that today the trader closed out the position at $1,620/oz. how much is the amount of profit/loss, and how much is the rate of return on the investment? (2) suppose that today the trader closed out the position at $1,570/oz. how much is the amount of profit/loss, and how much is the rate of return on the investment? 2. a trader enters into one march crude oil futures contract to sell 1,000 barrels at $90/barrel. the initial margin requirement is $9,000 and the maintenance margin is $6,000. what price change will lead to a margin call? please explain.