Investors can participate in the returns on the Standard and Poor’s 500 composite index in a variety of ways, and these alternatives exist because they differ in important respects. This article assesses one dimension of these differences—margin requirements.
Focusing on equity-related instruments, the author develops a model to simulate the values arising from several identical positions obtained by combinations of stocks and stock derivatives. The results are then used to assess the costs of margin requirements on alternative strategies. The primary conclusion is that the playing field is more level than a cursory focus on initial margin requirements might indicate. The costs associated with margin requirements on equities or stock indexes are essentially fixed costs. On the other hand, costs of margin requirements on derivatives, particularly on futures contracts, have a low fixed cost component but are more sensitive to the price of the underlying security. Investors may be choosing their strategies based on their tolerance for risk and may be sorting themselves into different markets, allowing all instruments to be financially viable.