NOBOX vs. PBDIX

Last updated Jun 24, 2026

NOBOX (Northern Bond Index Fund) and PBDIX (T. Rowe Price QM U.S. Bond Index Fund) are both mutual funds - NOBOX is a Intermediate Core Bond fund managed by Northern Funds, while PBDIX is a Total Bond Market fund managed by T. Rowe Price. Over the past 10 years, NOBOX returned 1.04%/yr vs 2.23%/yr for PBDIX. Their correlation of 0.88 suggests significant overlap in exposure. NOBOX charges 0.07%/yr vs 0.23%/yr for PBDIX.

Performance

NOBOX vs. PBDIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Northern Bond Index Fund (NOBOX) and T. Rowe Price QM U.S. Bond Index Fund (PBDIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, NOBOX achieves a -0.28% return, which is significantly lower than PBDIX's -0.12% return. Over the past 10 years, NOBOX has underperformed PBDIX with an annualized return of 1.04%, while PBDIX has yielded a comparatively higher 2.23% annualized return.

NOBOX

• 1D: -0.33%
• 1M: 0.70%
• YTD: -0.28%
• 6M: -0.18%
• 1Y: 3.90%
• 3Y*: 3.07%
• 5Y*: -0.76%
• 10Y*: 1.04%

PBDIX

• 1D: -0.31%
• 1M: 0.68%
• YTD: -0.12%
• 6M: 0.45%
• 1Y: 4.08%
• 3Y*: 5.85%
• 5Y*: 1.14%
• 10Y*: 2.23%

*Multi-year figures are annualized to reflect compound growth (CAGR)

NOBOX vs. PBDIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
NOBOX Northern Bond Index Fund	-0.28%	6.14%	0.82%	4.86%	-13.84%	-2.10%	7.20%	8.73%	-0.17%	3.60%
PBDIX T. Rowe Price QM U.S. Bond Index Fund	-0.12%	8.29%	4.75%	8.62%	-14.24%	-1.45%	8.17%	8.69%	-0.01%	3.83%

Correlation

The correlation between NOBOX and PBDIX is 0.80, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.80
Correlation (3Y) Calculated over the trailing 3-year period	0.89
Correlation (5Y) Calculated over the trailing 5-year period	0.93
Correlation (10Y) Calculated over the trailing 10-year period	0.90
Correlation (All Time) Calculated using the full available price history since Feb 28, 2007	0.88

The correlation between NOBOX and PBDIX shifts across timeframes, from 0.80 (1 year) to 0.93 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

NOBOX vs. PBDIX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

NOBOX

NOBOX Risk / Return Rank: 16
NOBOX Sharpe Ratio Rank: 16
NOBOX Sortino Ratio Rank: 17
NOBOX Omega Ratio Rank: 16
NOBOX Calmar Ratio Rank: 15
NOBOX Martin Ratio Rank: 14

PBDIX

PBDIX Risk / Return Rank: 17
PBDIX Sharpe Ratio Rank: 16
PBDIX Sortino Ratio Rank: 17
PBDIX Omega Ratio Rank: 15
PBDIX Calmar Ratio Rank: 18
PBDIX Martin Ratio Rank: 15

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

NOBOX vs. PBDIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Northern Bond Index Fund (NOBOX) and T. Rowe Price QM U.S. Bond Index Fund (PBDIX). 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.

	NOBOX	PBDIX	Difference
Sharpe ratio: Return per unit of total volatility	1.03	1.08	-0.05
Sortino ratio: Return per unit of downside risk	1.59	1.62	-0.03
Omega ratio: Gain probability vs. loss probability	1.19	1.19	0.00
Calmar ratio: Return relative to maximum drawdown	1.28	1.44	-0.16
Martin ratio: Return relative to average drawdown	3.57	3.93	-0.37

NOBOX vs. PBDIX - Sharpe Ratio Comparison

The current NOBOX Sharpe Ratio is 1.03, which is comparable to the PBDIX Sharpe Ratio of 1.08. The chart below compares the historical Sharpe Ratios of NOBOX and PBDIX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

NOBOX vs. PBDIX - Drawdown Comparison

The maximum NOBOX drawdown since its inception was -20.03%, roughly equal to the maximum PBDIX drawdown of -19.20%. Use the drawdown chart below to compare losses from any high point for NOBOX and PBDIX.

Drawdown Indicators

	NOBOX	PBDIX	Difference
Max Drawdown Largest peak-to-trough decline	-20.03%	-19.20%	-0.83%
Max Drawdown (1Y) Largest decline over 1 year	-3.28%	-3.08%	-0.20%
Max Drawdown (3Y) Largest decline over 3 years	-6.27%	-5.61%	-0.66%
Max Drawdown (5Y) Largest decline over 5 years	-19.15%	-19.10%	-0.05%
Max Drawdown (10Y) Largest decline over 10 years	-20.03%	-19.20%	-0.83%
Current Drawdown Current decline from peak	-6.23%	-1.91%	-4.32%
Average Drawdown Average peak-to-trough decline	-3.55%	-2.16%	-1.39%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.17%	1.11%	+0.06%

Volatility

NOBOX vs. PBDIX - Volatility Comparison

Northern Bond Index Fund (NOBOX) and T. Rowe Price QM U.S. Bond Index Fund (PBDIX) have volatilities of 1.30% and 1.24%, 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.

Volatility by Period

	NOBOX	PBDIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.30%	1.24%	+0.06%
Volatility (6M) Calculated over the trailing 6-month period	3.11%	3.15%	-0.04%
Volatility (1Y) Calculated over the trailing 1-year period	4.08%	4.13%	-0.05%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.10%	6.12%	-0.02%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.04%	5.03%	+0.01%

NOBOX vs. PBDIX - Expense Ratio Comparison

NOBOX has a 0.07% expense ratio, which is lower than PBDIX's 0.23% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

NOBOX vs. PBDIX - Dividend Comparison

NOBOX's dividend yield for the trailing twelve months is around 3.75%, less than PBDIX's 4.26% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NOBOX Northern Bond Index Fund	3.75%	2.88%	3.46%	2.63%	1.53%	2.10%	3.12%	3.18%	2.80%	2.77%	2.45%	2.61%
PBDIX T. Rowe Price QM U.S. Bond Index Fund	4.26%	5.19%	7.21%	6.39%	2.01%	1.84%	3.59%	3.18%	2.94%	2.75%	2.82%	2.99%

Frequently Asked Questions

Can I hold both NOBOX and PBDIX in my portfolio?

NOBOX and PBDIX have a correlation of 0.80, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, NOBOX or PBDIX?

NOBOX has higher volatility (1.30%) compared to PBDIX (1.24%). In terms of maximum drawdown, NOBOX dropped -20.03% vs PBDIX's -19.20%.

Which has better risk-adjusted returns?

PBDIX currently has the higher Sharpe Ratio (1.07 vs 1.03), 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.