Explanation

Correct Answer: A. A commodity index

Why this is correct:

1. Commodity indices typically use alternative weighting methods rather than market capitalization weighting. Common weighting methods for commodity indices include:

   • Production-weighted (based on global production quantities)
   • Consumption-weighted (based on global consumption patterns)
   • Equal-weighted (each commodity gets equal weight)
   • Liquidity-weighted (based on trading volumes)

2. Broad equity market indices (Option B) almost universally use market capitalization weighting. Examples include the S&P 500, MSCI World Index, and FTSE 100, which weight companies based on their market capitalization (share price × number of shares outstanding).

3. REIT indices (Option C) also typically use market capitalization weighting, similar to other equity indices. REITs are real estate investment trusts traded on stock exchanges, so their indices are constructed using standard equity index methodologies.

Key Concepts:

• Market capitalization weighting is the standard method for equity indices where each constituent's weight is proportional to its market value.
• Alternative weighting methods are used for commodity indices because commodities don't have "market capitalization" in the same way companies do. Commodities are physical goods, not companies with shares.
• Commodity index construction focuses on factors like production, consumption, or liquidity rather than market value.

Examples of commodity indices:

• S&P GSCI (formerly Goldman Sachs Commodity Index) - world production weighted
• Bloomberg Commodity Index - liquidity weighted
• Reuters/Jefferies CRB Index - equal weighted

Therefore, among the three options, only commodity indices do not use market capitalization as a weighting method.