GNMA vs. VOO
GNMA (iShares GNMA Bond ETF) and VOO (Vanguard S&P 500 ETF) are both exchange-traded funds - GNMA is a Mortgage Backed Securities fund tracking the Barclays Capital GNMA Index, while VOO is a S&P 500 fund tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, GNMA returned 1.22%/yr vs 15.61%/yr for VOO. At a 0.02 correlation, their price movements are largely independent. GNMA charges 0.15%/yr vs 0.03%/yr for VOO.
Performance
GNMA vs. VOO - Performance Comparison
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Returns By Period
In the year-to-date period, GNMA achieves a 0.92% return, which is significantly lower than VOO's 8.19% return. Over the past 10 years, GNMA has underperformed VOO with an annualized return of 1.22%, while VOO has yielded a comparatively higher 15.61% annualized return.
GNMA
- 1D
- 0.19%
- 1M
- 1.00%
- YTD
- 0.92%
- 6M
- 1.04%
- 1Y
- 5.77%
- 3Y*
- 4.27%
- 5Y*
- 0.64%
- 10Y*
- 1.22%
VOO
- 1D
- -1.42%
- 1M
- -1.34%
- YTD
- 8.19%
- 6M
- 7.24%
- 1Y
- 23.69%
- 3Y*
- 20.78%
- 5Y*
- 13.13%
- 10Y*
- 15.61%
GNMA vs. VOO - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
GNMA iShares GNMA Bond ETF | 0.92% | 8.25% | 1.07% | 5.34% | -10.83% | -1.86% | 3.51% | 5.85% | 0.85% | 1.74% |
VOO Vanguard S&P 500 ETF | 8.19% | 17.82% | 24.98% | 26.32% | -18.17% | 28.79% | 18.32% | 31.37% | -4.50% | 21.77% |
Correlation
The correlation between GNMA and VOO is 0.35, which is low. Their price movements are largely independent, making them effective diversification partners.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.35 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.23 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.20 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.08 |
Correlation (All Time) Calculated using the full available price history since Feb 21, 2012 | 0.02 |
Over the past year, GNMA and VOO have become more correlated (0.35) than their long-term average of 0.02, meaning their price movements have been converging.
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Return for Risk
GNMA vs. VOO — Risk / Return Rank
GNMA
VOO
GNMA vs. VOO - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares GNMA Bond ETF (GNMA) and Vanguard S&P 500 ETF (VOO). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.
| GNMA | VOO | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.55 | ||
| Sortino ratioReturn per unit of downside risk | -0.52 | ||
| Omega ratioGain probability vs. loss probability | 1.24 | 1.35 | -0.11 |
| Calmar ratioReturn relative to maximum drawdown | 2.22 | 2.67 | -0.46 |
| Martin ratioReturn relative to average drawdown | 6.66 | 11.96 | -5.30 |
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Drawdowns
GNMA vs. VOO - Drawdown Comparison
The maximum GNMA drawdown since its inception was -17.09%, smaller than the maximum VOO drawdown of -33.99%. Use the drawdown chart below to compare losses from any high point for GNMA and VOO.
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Drawdown Indicators
| GNMA | VOO | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -17.09% | -33.99% | +16.90% |
Max Drawdown (1Y)Largest decline over 1 year | -2.61% | -8.90% | +6.29% |
Max Drawdown (3Y)Largest decline over 3 years | -7.13% | -18.69% | +11.56% |
Max Drawdown (5Y)Largest decline over 5 years | -15.83% | -24.52% | +8.69% |
Max Drawdown (10Y)Largest decline over 10 years | -17.09% | -33.99% | +16.90% |
Current DrawdownCurrent decline from peak | -1.05% | -3.14% | +2.09% |
Average DrawdownAverage peak-to-trough decline | -3.65% | -3.68% | +0.03% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.87% | 1.99% | -1.12% |
Volatility
GNMA vs. VOO - Volatility Comparison
The current volatility for iShares GNMA Bond ETF (GNMA) is 1.38%, while Vanguard S&P 500 ETF (VOO) has a volatility of 4.83%. This indicates that GNMA experiences smaller price fluctuations and is considered to be less risky than VOO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| GNMA | VOO | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.38% | 4.83% | -3.45% |
Volatility (6M)Calculated over the trailing 6-month period | 3.27% | 9.82% | -6.55% |
Volatility (1Y)Calculated over the trailing 1-year period | 4.26% | 12.46% | -8.20% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.63% | 16.91% | -10.28% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.14% | 18.02% | -12.88% |
GNMA vs. VOO - Expense Ratio Comparison
GNMA has a 0.15% expense ratio, which is higher than VOO's 0.03% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.
Dividends
GNMA vs. VOO - Dividend Comparison
GNMA's dividend yield for the trailing twelve months is around 4.22%, more than VOO's 1.05% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
GNMA iShares GNMA Bond ETF | 4.22% | 4.19% | 4.15% | 3.43% | 2.01% | 0.64% | 1.89% | 2.61% | 2.41% | 2.15% | 1.89% | 1.50% |
VOO Vanguard S&P 500 ETF | 1.05% | 1.13% | 1.24% | 1.46% | 1.69% | 1.25% | 1.54% | 1.88% | 2.06% | 1.78% | 2.02% | 2.10% |
Frequently Asked Questions
GNMA and VOO have a correlation of 0.35, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
VOO has higher volatility (4.83%) compared to GNMA (1.38%). In terms of maximum drawdown, GNMA dropped -17.09% vs VOO's -33.99%.
On 10-year performance, VOO leads with 15.61% vs 1.22% for GNMA. On fees, VOO is cheaper at 0.03% per year. On volatility, GNMA has been the lower-risk option at 1.38%. The better choice depends on whether you care most about return, fees, risk, or income.
Over the 10-year period, VOO has performed better with a 15.61% return vs 1.22%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.
VOO is cheaper with a 0.03% expense ratio, compared with 0.15% for GNMA.
GNMA has the higher dividend yield at 4.22%, compared with 1.05% for VOO.
GNMA is categorized as Mortgage Backed Securities, while VOO is S&P 500. GNMA tracks Barclays Capital GNMA Index, while VOO tracks S&P 500 Index. They also come from different issuers: iShares and Vanguard. Their fees differ too: 0.15% for GNMA and 0.03% for VOO.
VOO currently has the higher Sharpe Ratio (1.91 vs 1.36), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.
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