Overnight Interest = Settlement Price × Contract Size × Lot Size (Long / Short) × Days × Overnight Interest Rate (Long / Short) ÷ 360 Example: Short Selling 1 lot of EURUSD, the closing price of the trading day is 1.13700, the overnight interest of holding the position for 1 day = 1.13700 × 100,000 × 1 × (-0.10%) ÷ 360 = $0.32 USD