In the spot market, due to the devaluation of the pound, the loss: 500,000 * (1.3200-1.2800) = 20,000.

Short in the futures market, due to the depreciation of the pound, the profit: 8 * 62500 * (1.3220-1.2820) = 20000.

The net profit and loss is 0, achieving complete preservation.