Equal-Weight Index
Quick Definition
An index where each constituent stock receives the same allocation weight regardless of market capitalization, giving smaller companies the same influence as larger ones.
What Is Equal-Weight Index?
An equal-weight index assigns the same percentage allocation to every stock in the index, regardless of company size. For example, in an equal-weight S&P 500 index, each of the 500 stocks gets a 0.20% weight, meaning Apple and a small-cap company in the index each represent the same portion.
Equal-Weight vs Cap-Weight Comparison:
| Feature | Equal-Weight | Cap-Weight |
|---|---|---|
| Apple weight (S&P 500) | 0.20% | ~7% |
| Small company weight | 0.20% | ~0.01% |
| Rebalancing | Quarterly (sell winners, buy losers) | Rarely needed |
| Turnover | Higher | Lower |
| Sector exposure | More balanced | Tech-heavy |
Popular Equal-Weight Products:
| Fund | Tracks | Expense Ratio |
|---|---|---|
| RSP | Equal-Weight S&P 500 | 0.20% |
| EQAL | Equal-Weight US Market | 0.20% |
| EWRI | Equal-Weight Russell 1000 | 0.20% |
Advantages:
- Less concentration — no mega-cap dominance (top 10 stocks in cap-weight S&P 500 make up ~35%)
- Small-cap tilt — gives more weight to smaller companies
- Built-in rebalancing — systematically sells high, buys low
- Sector diversification — more balanced across sectors
Disadvantages:
- Higher turnover — quarterly rebalancing increases trading costs
- Higher expense ratios — typically 0.20%+ vs 0.03% for cap-weight
- Tax inefficiency — more frequent rebalancing triggers capital gains
- Underperformance when mega-caps lead — misses the full benefit of big tech rallies
- Tracking complexity — harder to replicate exactly
Historical Performance: Equal-weight has historically outperformed cap-weight over long periods due to the "small-cap premium" and rebalancing bonus, but it can significantly underperform during mega-cap-led bull markets (like 2020-2024).
Equal-Weight Index Example
- 1In RSP (equal-weight S&P 500), Apple gets the same 0.2% weight as the smallest S&P 500 company
- 2RSP outperformed SPY from 2003-2014 but underperformed from 2015-2024 as mega-cap tech dominated
Related Terms
Cap-Weighted Index
An index where each stock's weight is proportional to its total market capitalization, meaning larger companies have a bigger impact on index performance.
Index Investing
A passive strategy that aims to match market returns by holding all securities in a market index in proportion to their weights.
S&P 500 Index Fund
A fund that tracks the S&P 500 index by holding all 500 large-cap US stocks in proportion to their market capitalization.
Smart Beta ETF
An ETF that uses alternative index construction rules based on factors like value, momentum, quality, or low volatility instead of traditional market-cap weighting.
Exchange-Traded Fund (ETF)
A basket of securities that trades on an exchange like a stock, offering diversification with the flexibility of intraday trading.
Vanguard
The world's largest mutual fund company, founded by John Bogle in 1975, pioneering low-cost index investing with a unique investor-owned structure.
Expand Your Financial Vocabulary
Explore 130+ financial terms with definitions, examples, and formulas
Browse ETFs & Index Investing Terms