PNIIX vs. RBFFX
PNIIX (Principal Bond Market Index Fund) and RBFFX (American Funds The Bond Fund of America) are both Intermediate Core Bond funds. Over the past 10 years, PNIIX returned 1.44%/yr vs 1.99%/yr for RBFFX. Their correlation of 0.91 suggests significant overlap in exposure. PNIIX charges 0.15%/yr vs 0.29%/yr for RBFFX.
Performance
PNIIX vs. RBFFX - Performance Comparison
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Returns By Period
In the year-to-date period, PNIIX achieves a 0.59% return, which is significantly higher than RBFFX's 0.13% return. Over the past 10 years, PNIIX has underperformed RBFFX with an annualized return of 1.44%, while RBFFX has yielded a comparatively higher 1.99% annualized return.
PNIIX
- 1D
- 0.23%
- 1M
- 0.82%
- YTD
- 0.59%
- 6M
- 0.59%
- 1Y
- 4.61%
- 3Y*
- 3.93%
- 5Y*
- -0.08%
- 10Y*
- 1.44%
RBFFX
- 1D
- 0.18%
- 1M
- 0.91%
- YTD
- 0.13%
- 6M
- 0.59%
- 1Y
- 4.60%
- 3Y*
- 4.01%
- 5Y*
- -0.00%
- 10Y*
- 1.99%
PNIIX vs. RBFFX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
PNIIX Principal Bond Market Index Fund | 0.59% | 7.01% | 1.17% | 5.55% | -13.26% | -1.68% | 7.28% | 8.47% | -0.20% | 3.31% |
RBFFX American Funds The Bond Fund of America | 0.13% | 7.49% | 1.47% | 4.65% | -13.03% | -0.64% | 11.07% | 8.13% | 0.17% | 3.53% |
Correlation
The correlation between PNIIX and RBFFX is 0.88, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.88 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.93 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.95 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.92 |
Correlation (All Time) Calculated using the full available price history since Dec 31, 2009 | 0.91 |
The correlation between PNIIX and RBFFX has been stable across timeframes, ranging from 0.88 to 0.95 - a consistent structural relationship.
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Return for Risk
PNIIX vs. RBFFX — Risk / Return Rank
PNIIX
RBFFX
PNIIX vs. RBFFX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Principal Bond Market Index Fund (PNIIX) and American Funds The Bond Fund of America (RBFFX). 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.
| PNIIX | RBFFX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +0.01 | ||
| Sortino ratioReturn per unit of downside risk | +0.01 | ||
| Omega ratioGain probability vs. loss probability | 1.22 | 1.21 | 0.00 |
| Calmar ratioReturn relative to maximum drawdown | 1.68 | 1.53 | +0.15 |
| Martin ratioReturn relative to average drawdown | 4.84 | 4.29 | +0.55 |
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Drawdowns
PNIIX vs. RBFFX - Drawdown Comparison
The maximum PNIIX drawdown since its inception was -18.76%, which is greater than RBFFX's maximum drawdown of -17.62%. Use the drawdown chart below to compare losses from any high point for PNIIX and RBFFX.
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Drawdown Indicators
| PNIIX | RBFFX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -18.76% | -17.62% | -1.14% |
Max Drawdown (1Y)Largest decline over 1 year | -2.76% | -3.09% | +0.33% |
Max Drawdown (3Y)Largest decline over 3 years | -6.25% | -6.11% | -0.14% |
Max Drawdown (5Y)Largest decline over 5 years | -18.14% | -17.62% | -0.52% |
Max Drawdown (10Y)Largest decline over 10 years | -18.76% | -17.62% | -1.14% |
Current DrawdownCurrent decline from peak | -2.53% | -1.59% | -0.94% |
Average DrawdownAverage peak-to-trough decline | -3.44% | -2.81% | -0.63% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 0.95% | 1.09% | -0.14% |
Volatility
PNIIX vs. RBFFX - Volatility Comparison
Principal Bond Market Index Fund (PNIIX) and American Funds The Bond Fund of America (RBFFX) have volatilities of 1.24% and 1.23%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| PNIIX | RBFFX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.24% | 1.23% | +0.01% |
Volatility (6M)Calculated over the trailing 6-month period | 2.81% | 2.90% | -0.09% |
Volatility (1Y)Calculated over the trailing 1-year period | 3.82% | 3.90% | -0.08% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 6.32% | 5.97% | +0.35% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 5.09% | 4.90% | +0.19% |
PNIIX vs. RBFFX - Expense Ratio Comparison
PNIIX has a 0.15% expense ratio, which is lower than RBFFX's 0.29% expense ratio.
Dividends
PNIIX vs. RBFFX - Dividend Comparison
PNIIX's dividend yield for the trailing twelve months is around 3.99%, less than RBFFX's 4.45% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
PNIIX Principal Bond Market Index Fund | 3.99% | 4.01% | 3.60% | 4.18% | 1.66% | 2.03% | 18.60% | 2.40% | 2.51% | 2.35% | 1.78% | 2.10% |
RBFFX American Funds The Bond Fund of America | 4.45% | 4.43% | 4.61% | 3.53% | 2.42% | 2.31% | 5.34% | 3.76% | 2.67% | 2.14% | 2.07% | 2.30% |
Frequently Asked Questions
PNIIX and RBFFX have a correlation of 0.88, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
PNIIX has higher volatility (1.24%) compared to RBFFX (1.23%). In terms of maximum drawdown, PNIIX dropped -18.76% vs RBFFX's -17.62%.
PNIIX currently has the higher Sharpe Ratio (1.21 vs 1.21), 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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