The one year forward contract on crude oil trades at $100 a barrel. The spot price of crude is $90 a barrel. Storage costs are $4 a barrel and the risk free rate is 5%. Is there arbitrage? If yes show how you would trade it? Show all calculations and cash flows.

Suppose there is margin requirement of 50% for trading in a forward contract. Is there arbitrage? If yes show how you would trade it? Show all calculations and cash flows.