Warren Buffett stated in the 2009 Letter to Shareholders: "Our derivatives dealings require our counterparties to make payments to us when contracts are initiated. Berkshire therefore always holds the money, which leaves us assuming no meaningful counterparty risk." Buffett also was not required to make collateral payments to counterparties on these contracts. With these considerations in mind, explain how you think Buffett might have evaluated the costs and benefits of the following long investment strategies: purchased call, written put, long index swap, long index futures, written collar.