🤝 BFF Take
SPY for Low Cost and Simplicity. RSP for Reduced Concentration Risk.
RSP and SPY track the same 503-company universe, but RSP (Invesco S&P 500 Equal Weight) weights each at about 0.2% while SPY (SPDR S&P 500) weights by market cap. As of 2026, SPY's top 10 holdings account for over 35% of the fund, primarily mega-cap tech. RSP caps each company at roughly 0.2%, rebalancing quarterly. Equal weighting has historically outperformed market-cap weighting over long periods because it forces a "buy low, sell high" rebalance discipline and provides more exposure to smaller S&P 500 companies that historically earn a size premium. However, RSP charges 0.20% vs SPY's 0.0945%, and it can lag significantly during periods when mega-cap growth stocks dominate returns, as in 2023-2024. RSP is the better choice for investors concerned about concentration. SPY is the better choice for investors who want the cheapest, most liquid S&P 500 exposure.
📋 Quick Takeaways
⚖️RSP: 0.20% ER, ~0.2% per stock equally. SPY: 0.0945% ER, top 10 stocks = 35%+ of fund.
📊Equal weighting has outperformed market-cap weighting over most 10-20 year periods. It lagged in 2023-2024 when mega-cap tech dominated.
🎯SPY for cheapest S&P 500 exposure. RSP to reduce AAPL/NVDA/MSFT concentration without leaving the index.
📊 Data-Based Take: SPY has the lower fee
Whether the lower-cost fund suits your situation depends on your existing holdings, account type, tax situation, and how you use each fund. This is a cost comparison, not a personalized recommendation.
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Reviewed by a CFA® Charterholder · Data updated Jun 2026 · Educational only, not financial advice
RSP
Invesco S&P 500 Equal Weight ETF
SPY
SPDR S&P 500 ETF Trust
📋 RSP vs SPY — Key Facts Side by Side
| Metric |
RSP |
SPY |
| Fund Name |
Invesco S&P 500 Equal Weight ETF |
SPDR S&P 500 ETF Trust |
| Issuer |
Invesco |
State Street |
| Tracks Index |
S&P 500 Equal Weight Index |
S&P 500 |
| Expense Ratio |
0.20% |
0.09% ✓ |
| Cost per $10K/yr |
$20.00 |
$9.45 |
| AUM |
$60B |
$560B |
| Holdings |
503 |
503 |
| Inception |
2003 |
1993 |
| 1-Year Return |
+15.10% |
+26.30% |
| 3-Year Return |
+8.50% |
+10.10% |
| 5-Year Return |
+13.20% |
+15.80% |
| Avg Bid-Ask Spread |
0.01% |
0.00% |
Data from ETF BFF database. Returns are annualised. Not investment advice.
📊 RSP vs SPY — Annualised Returns
Annualised returns (trailing, price-based). Past performance does not guarantee future results.
🎯 Should You Buy RSP or SPY?
Choose if...
RSP
- You want focused large-cap US stock exposure via S&P 500 Equal Weight Index
- You already use Invesco and prefer staying within their fund family
Choose if...
SPY
- You want the lowest fees — saves ~$11/yr per $10K vs RSP
- You want focused large-cap US stock exposure via S&P 500
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❓ RSP vs SPY — Frequently Asked Questions
Does RSP outperform SPY?
Over long periods, RSP has outperformed SPY. Equal weighting provides more exposure to mid-size S&P 500 companies that historically earn a size premium over mega-caps. However, RSP significantly underperformed during 2023-2025 when Apple, Nvidia, Microsoft, and Meta drove a disproportionate share of S&P 500 returns. RSP's outperformance tends to come during value-led or mean-reverting markets; it lags in concentrated mega-cap growth rallies.
Why would I choose RSP over VOO or SPY?
The main reason to choose RSP is concentration concern. By 2026, the top 10 companies in the S&P 500 accounted for over 35% of its market cap, the highest concentration level since the late 1990s dot-com era. RSP eliminates that concentration by treating every company equally, rebalancing quarterly. This provides more exposure to the 493 smaller S&P 500 companies and reduces single-stock and single-sector risk.
What is the expense ratio difference between RSP and SPY?
RSP charges 0.20% ($20/yr per $10K). SPY charges 0.0945% ($9.45/yr per $10K). On a $100,000 portfolio, the difference is about $106/yr. Over 30 years at equal returns, that gap compounds meaningfully. RSP's historical outperformance over full market cycles has more than covered the cost difference for long-term investors.
How often does RSP rebalance?
RSP rebalances quarterly: in March, June, September, and December. At each rebalance, outperforming stocks are trimmed back toward the 0.2% target weight and underperforming stocks are bought up. This systematic sell-high, buy-low mechanism is a core reason equal-weighted strategies have historically produced better long-run results than market-cap weighting, at the cost of higher turnover and taxes in taxable accounts.
New to ETF investing? See answers to the most common ETF questions →
ℹ️ Data shown is for educational purposes and may not reflect the most current figures. Returns are trailing price-based and exclude dividend reinvestment. Past performance does not guarantee future results. ETF BFF is not a licensed financial advisor — this is not personalized financial advice.