RFBAX vs. FUMBX

Last updated Jun 24, 2026

RFBAX (Davis Government Bond Fund) and FUMBX (Fidelity Short-Term Treasury Bond Index Fund) are both mutual funds - RFBAX is a Government Bonds fund managed by Davis Funds, while FUMBX is a Short-Term Bond fund tracking the Bloomberg U.S. 1-5 Year Treasury Bond Index. Over the past 5 years, RFBAX returned 1.34%/yr vs 1.31%/yr for FUMBX. A 0.58 correlation means they provide meaningful diversification when combined. RFBAX charges 1.00%/yr vs 0.03%/yr for FUMBX.

Performance

RFBAX vs. FUMBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Davis Government Bond Fund (RFBAX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RFBAX achieves a 0.88% return, which is significantly higher than FUMBX's -0.11% return.

RFBAX

• 1D: -0.19%
• 1M: 0.25%
• YTD: 0.88%
• 6M: 1.15%
• 1Y: 3.28%
• 3Y*: 3.97%
• 5Y*: 1.34%
• 10Y*: 1.06%

FUMBX

• 1D: -0.10%
• 1M: 0.16%
• YTD: -0.11%
• 6M: 0.24%
• 1Y: 2.69%
• 3Y*: 4.03%
• 5Y*: 1.31%
• 10Y*: —

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

RFBAX vs. FUMBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
RFBAX Davis Government Bond Fund	0.88%	4.49%	4.33%	3.63%	-5.29%	-1.48%	1.69%	3.23%	0.42%	-0.21%
FUMBX Fidelity Short-Term Treasury Bond Index Fund	-0.11%	5.83%	3.25%	4.47%	-5.84%	-1.38%	4.22%	4.19%	1.47%	-0.33%

Correlation

The correlation between RFBAX and FUMBX is 0.56, 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	0.56
Correlation (3Y) Calculated over the trailing 3-year period	0.57
Correlation (5Y) Calculated over the trailing 5-year period	0.63
Correlation (All Time) Calculated using the full available price history since Oct 19, 2017	0.58

The correlation between RFBAX and FUMBX has been stable across timeframes, ranging from 0.56 to 0.63 - a consistent structural relationship.

Return for Risk

RFBAX vs. FUMBX — Risk / Return Rank

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

RFBAX

RFBAX Risk / Return Rank: 71
RFBAX Sharpe Ratio Rank: 42
RFBAX Sortino Ratio Rank: 54
RFBAX Omega Ratio Rank: 80
RFBAX Calmar Ratio Rank: 89
RFBAX Martin Ratio Rank: 90

FUMBX

FUMBX Risk / Return Rank: 29
FUMBX Sharpe Ratio Rank: 27
FUMBX Sortino Ratio Rank: 32
FUMBX Omega Ratio Rank: 32
FUMBX Calmar Ratio Rank: 29
FUMBX Martin Ratio Rank: 25

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.

RFBAX vs. FUMBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Davis Government Bond Fund (RFBAX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). 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.

	RFBAX	FUMBX	Difference
Sharpe ratio: Return per unit of total volatility	1.76	1.39	+0.37
Sortino ratio: Return per unit of downside risk	2.84	2.19	+0.65
Omega ratio: Gain probability vs. loss probability	1.48	1.28	+0.20
Calmar ratio: Return relative to maximum drawdown	4.27	1.89	+2.39
Martin ratio: Return relative to average drawdown	16.74	5.55	+11.19

RFBAX vs. FUMBX - Sharpe Ratio Comparison

The current RFBAX Sharpe Ratio is 1.76, which is comparable to the FUMBX Sharpe Ratio of 1.39. The chart below compares the historical Sharpe Ratios of RFBAX and FUMBX, 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

RFBAX vs. FUMBX - Drawdown Comparison

The maximum RFBAX drawdown since its inception was -8.03%, smaller than the maximum FUMBX drawdown of -8.83%. Use the drawdown chart below to compare losses from any high point for RFBAX and FUMBX.

Drawdown Indicators

	RFBAX	FUMBX	Difference
Max Drawdown Largest peak-to-trough decline	-8.03%	-8.83%	+0.80%
Max Drawdown (1Y) Largest decline over 1 year	-0.77%	-1.54%	+0.77%
Max Drawdown (3Y) Largest decline over 3 years	-0.88%	-1.57%	+0.69%
Max Drawdown (5Y) Largest decline over 5 years	-7.50%	-8.60%	+1.10%
Max Drawdown (10Y) Largest decline over 10 years	-8.03%	—	—
Current Drawdown Current decline from peak	-0.19%	-1.06%	+0.87%
Average Drawdown Average peak-to-trough decline	-1.18%	-1.85%	+0.67%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.20%	0.52%	-0.32%

Volatility

RFBAX vs. FUMBX - Volatility Comparison

The current volatility for Davis Government Bond Fund (RFBAX) is 0.55%, while Fidelity Short-Term Treasury Bond Index Fund (FUMBX) has a volatility of 0.70%. This indicates that RFBAX experiences smaller price fluctuations and is considered to be less risky than FUMBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RFBAX	FUMBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.55%	0.70%	-0.15%
Volatility (6M) Calculated over the trailing 6-month period	1.30%	1.56%	-0.26%
Volatility (1Y) Calculated over the trailing 1-year period	1.88%	2.08%	-0.20%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.10%	2.93%	-0.83%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.79%	2.49%	-0.70%

RFBAX vs. FUMBX - Expense Ratio Comparison

RFBAX has a 1.00% expense ratio, which is higher than FUMBX's 0.03% expense ratio.

Dividends

RFBAX vs. FUMBX - Dividend Comparison

RFBAX's dividend yield for the trailing twelve months is around 3.04%, less than FUMBX's 3.77% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FUMBX Fidelity Short-Term Treasury Bond Index Fund	3.77%	3.51%	2.91%	1.64%	0.86%	1.15%	1.41%	1.88%	1.64%	0.34%	0.00%	0.00%
RFBAX Davis Government Bond Fund	3.04%	3.01%	3.23%	2.15%	0.80%	0.57%	0.93%	1.67%	1.17%	0.59%	0.68%	0.75%

Frequently Asked Questions

Can I hold both RFBAX and FUMBX in my portfolio?

RFBAX and FUMBX have a correlation of 0.56, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RFBAX or FUMBX?

FUMBX has higher volatility (0.70%) compared to RFBAX (0.55%). In terms of maximum drawdown, RFBAX dropped -8.03% vs FUMBX's -8.83%.

Which has better risk-adjusted returns?

RFBAX currently has the higher Sharpe Ratio (1.76 vs 1.39), 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.