The S&P 500 and the equal-weight S&P 500 hold the same companies. The difference is how much of each one they hold.
In the regular S&P 500, the biggest companies count the most. In the equal-weight version, each company is reset to the same slice, about 0.2% of the index, every quarter.
That one choice has made a big difference to returns in some years. Here is how the two versions work and how they have compared.
How the regular S&P 500 is weighted
The standard S&P 500 weights each company by the market value of its shares that are available to trade. Investors often call this cap weighting.
As of September 30, 2026, the 10 largest holdings made up about 39% of the index. A move in one of those stocks counts for far more than the same move in a smaller company. See the top 10 S&P 500 stocks for their role in 2026.
How the equal-weight S&P 500 works
The S&P 500 Equal Weight Index launched on January 8, 2003. It holds the same companies as the S&P 500 but sets the same target weight for each one.
Prices drift between rebalances, so the index resets every quarter. The reset happens after the close on the third Friday of March, June, September and December.
Right after a rebalance, the 10 biggest companies make up only about 2% of the equal-weight index. That compares with about 39% of the regular index as of September 30, 2026.
Each quarter's reset trims the stocks that have gained the most since the last one and adds to the ones that have gained the least.
The two funds that track them
SPY, the SPDR S&P 500 ETF Trust, tracks the regular S&P 500. It launched on January 22, 1993. As of October 2026, its gross expense ratio was 0.0945% a year.
RSP, the Invesco S&P 500 Equal Weight ETF, tracks the equal-weight index. It launched on April 24, 2003. As of October 2026, it charged 0.20% a year.
Equal weight vs the S&P 500 in 2026
Counting dividends, RSP was ahead of SPY for the year on 158 of 202 trading days through October 21, 2026. Its biggest lead was 6.4 percentage points on February 27, 2026.
Then the lead reversed. By October 7, 2026, the S&P 500 was up 14.0% for the year on price, against 9.9% for RSP. See how the 2026 race flipped.
The gap narrowed after that. Through October 21, 2026, counting dividends, RSP was up 14.4% for the year and SPY 14.3%.
The RSP to SPY ratio
One simple way to track the race is to divide RSP's price by SPY's. When the line falls, RSP is losing ground to SPY.
The ratio peaked at 0.394 on April 6, 2015. On October 7, 2026, it hit 0.271, its lowest since RSP began trading in 2003 and about 31% below that peak. On October 21, 2026, it stood at 0.280.
The long run has had two phases. From the end of 2003 to the end of 2014, the ratio climbed about 28%. From the end of 2022 through October 21, 2026, it lost about a quarter of its value. See the RSP to SPY ratio chart.
Which has done better over time
Counting dividends, RSP beat SPY in 10 of the 22 calendar years from 2004 through 2025.
Its best year relative to SPY was 2009, when RSP gained about 45% and SPY 26.4%.
Its worst stretch was 2023 and 2024. RSP trailed by 12.5 points in 2023 and 12.1 points in 2024.
In the 2022 bear market, RSP fell 11.6% while SPY fell 18.2%.
Over the full run, the two have ended up close. From May 1, 2003, through October 21, 2026, SPY returned 11.5% a year and RSP slightly less, counting dividends.
Why the gap matters
The gap between the two is one way to measure market breadth, meaning how widely gains are spread across stocks. When equal weight trails, the index's largest companies have done better than the typical member.
That shows up in how the median stock is doing. It also shows up in the Magnificent 7 returns gap in 2026.
Strategists have weighed in on narrow breadth, including Mike Wilson of Morgan Stanley on narrow market breadth and Michael Cembalest of JPMorgan on stock pickers and breadth. Barron's Josh Schafer joined us for a Full Signal episode on breadth.
Neither version has led in every period, and past returns don't predict future ones. Cap weight puts more money in the largest companies. Equal weight spreads it evenly and has a higher fee.
For the full index, start with our S&P 500 guide, and browse more stock market charts.
Frequently asked questions
What is the equal-weight S&P 500?
It's a version of the S&P 500 that gives each company the same target weight, about 0.2%, instead of weighting by market value. It launched on January 8, 2003, and rebalances every quarter.
What is the difference between RSP and SPY?
SPY tracks the regular S&P 500, and RSP tracks the equal-weight version. They hold the same companies in very different amounts. As of October 2026, SPY charged 0.0945% a year and RSP 0.20%.
Has equal weight beaten the S&P 500 over time?
Not quite. From May 1, 2003, through October 21, 2026, SPY returned 11.5% a year and RSP slightly less, counting dividends. RSP won in 10 of the 22 calendar years from 2004 through 2025.
When has equal weight lagged the most?
In 2023 and 2024, when RSP trailed SPY by 12.5 and 12.1 percentage points, counting dividends. From the end of 2022 through October 21, 2026, the RSP to SPY ratio fell about a quarter.
What is the RSP to SPY ratio?
It's RSP's price divided by SPY's. A falling ratio means RSP is losing ground to SPY. On October 7, 2026, it hit 0.271, its lowest since RSP began trading in 2003.
How often does the equal-weight S&P 500 rebalance?
Every quarter, after the close on the third Friday of March, June, September and December.
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