Step 1: Adapting Cost of Carry for Equity Indices:
Equity indices do not have physical properties, so they do not incur storage, transportation, or insurance costs.
Step 2: Factoring in Financing and Dividends:
• Financing Cost: The interest cost of capital used to purchase the index shares.
• Dividends: Cash distributions received from those shares, which reduce the net cost of holding the position.
Step 3: Formulating the Equation:
Subtracting dividend income from the financing cost yields the net cost of carrying the equity position:
$$\text{Cost of Carry} = \text{Financing Cost} - \text{Dividends (C)}$$