Research snapshot: July 17, 2026. VOO, IVV, and SPY all seek to track the S&P 500, but their published expense ratios are not identical. ETFSift built a controlled model to isolate one question: if the market exposure and investor cash flows are held constant, how much can the fee difference change the ending balance?
This is an original ETFSift calculation, not a backtest and not a return forecast. The model deliberately removes security selection, market timing, taxes, bid-ask spreads, and tracking differences so that the expense ratio is the only variable.
Key Findings
- Vanguard reports a 0.03% expense ratio for VOO, and iShares reports 0.03% for IVV.
- State Street reports a 0.0945% gross expense ratio for SPY.
- With a $10,000 starting balance, $500 invested at the end of every month, and a hypothetical 7% annual gross return, the modeled 30-year balances are $686,829 for VOO or IVV and $677,642 for SPY.
- The modeled 30-year gap between the 0.03% funds and SPY is $9,187. This is a fee-only estimate, not evidence that one fund will outperform by that amount.
Published Fee Dataset
| Fund | Index objective | Published expense ratio | Issuer source |
|---|---|---|---|
| VOO | S&P 500 | 0.03% | Vanguard |
| IVV | S&P 500 | 0.03% | iShares |
| SPY | S&P 500 | 0.0945% gross | State Street |
The three funds target the same benchmark, so their holdings should be broadly similar. They are still different legal products with different trading histories, liquidity profiles, spreads, securities-lending practices, and tracking results. This study does not assume those implementation differences are zero in the real world; it sets them aside to isolate the annual fee.
Methodology and Reproducible Assumptions
- Starting investment: $10,000.
- Monthly contribution: $500 deposited at the end of each month.
- Gross return assumption: 7.00% per year, compounded monthly. This is an illustration, not an expected return.
- Fee treatment: each fund's stated annual expense ratio is subtracted from the gross annual rate, then divided by 12 for the monthly model.
- Horizons: 10, 20, and 30 years.
- Excluded: taxes, commissions, spreads, tracking error, premiums or discounts, cash drag, and changes to future fees.
The calculation is the future value of the initial balance plus an ordinary annuity of monthly contributions:
ending balance = initial × (1 + monthly net rate)^months + contribution × (((1 + monthly net rate)^months - 1) / monthly net rate)
The monthly net rate is (7.00% - expense ratio) / 12. Rounded dollar results can be reproduced in a spreadsheet using the same inputs.
Modeled Ending Balances
| Horizon | No-fee baseline | VOO (0.03%) | IVV (0.03%) | SPY (0.0945%) |
|---|---|---|---|---|
| 10 years | $106,639 | $106,436 | $106,436 | $106,002 |
| 20 years | $300,851 | $299,664 | $299,664 | $297,131 |
| 30 years | $691,150 | $686,829 | $686,829 | $677,642 |
Modeled Fee Drag Versus the No-Fee Baseline
| Horizon | VOO fee drag | IVV fee drag | SPY fee drag |
|---|---|---|---|
| 10 years | $203 | $203 | $637 |
| 20 years | $1,187 | $1,187 | $3,720 |
| 30 years | $4,322 | $4,322 | $13,509 |
The gap grows nonlinearly because every dollar paid in fees also loses the opportunity to compound later. In this model, the 0.0645 percentage-point annual difference between 0.03% and 0.0945% produces a $434 ending-balance gap after 10 years, $2,533 after 20 years, and $9,187 after 30 years.
What the Model Does Not Prove
The calculation does not prove that VOO or IVV is always better than SPY. For an active trader, execution quality, intraday liquidity, and the options market can matter more than a small annual fee difference. For a long-term investor making recurring contributions, recurring cost may deserve more weight. Account features, fractional shares, tax lots, and existing unrealized gains can also affect the practical decision.
Expense ratios can change. The figures above are a dated research snapshot and should be checked against each issuer's latest prospectus before acting. Actual fund returns will also differ because of tracking, portfolio operations, and market conditions.
How to Compare the Funds in Context
Use the ETFSift VOO vs IVV vs SPY comparison to review returns, income, AUM, and risk metrics alongside fees. The S&P 500 ETF guide explains where trading use and fund structure may matter. Our research methodology describes how ETFSift separates reported facts, calculations, and interpretation.
Bottom Line
When funds track the same index, fees are one of the few differences an investor can identify in advance. The annual gap here looks small, but the controlled model shows why holding period and recurring contributions make it more visible. Cost is still only one decision variable: liquidity, taxes, portfolio fit, and investor behavior remain part of the full comparison.
Primary Sources
- Vanguard official VOO profile
- iShares official IVV profile
- State Street official SPY profile
- Investor.gov ETF education
Educational research only. This model is not personalized investment, tax, or financial advice.