Portfolio margin account maintenance margin = 650,000 USD. (4) Intertemporal covered call portfolio of futures and options: Sell 678 contracts of BTCUSD bi-weekly call options at 70,000 USD and buy 13,000 contracts of BTCUSD quarterly futures. Unified account maintenance margin = 560,000 USD. Portfolio margin account maintenance margin = 200,000 USD. 13. How is Spot-derivatives risk offset carried out in the Portfolio margin account?