BTTRX vs. RFBAX

Last updated Jun 4, 2026

BTTRX (American Century Zero Coupon 2025 Fund) and RFBAX (Davis Government Bond Fund) are both Government Bonds funds. A 0.55 correlation means they provide meaningful diversification when combined. BTTRX charges 0.54%/yr vs 1.00%/yr for RFBAX.

Performance

BTTRX vs. RFBAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Zero Coupon 2025 Fund (BTTRX) and Davis Government Bond Fund (RFBAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

BTTRX

• 1D: —
• 1M: —
• YTD: —
• 6M: —
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

RFBAX

• 1D: 0.00%
• 1M: 0.06%
• YTD: 0.88%
• 6M: 1.15%
• 1Y: 3.48%
• 3Y*: 3.97%
• 5Y*: 1.31%
• 10Y*: 1.08%

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

BTTRX vs. RFBAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BTTRX American Century Zero Coupon 2025 Fund	0.00%	2.79%	9.54%	7.82%	-7.63%	-2.65%	17.73%	11.43%	5.77%	1.22%
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%

Correlation

The correlation between BTTRX and RFBAX is 0.09, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.09
Correlation (3Y) Calculated over the trailing 3-year period	0.39
Correlation (5Y) Calculated over the trailing 5-year period	0.55
Correlation (10Y) Calculated over the trailing 10-year period	0.43
Correlation (All Time) Calculated using the full available price history since Feb 16, 1996	0.55

Over the past year, the correlation between BTTRX and RFBAX has dropped to 0.09 - well below their long-term average of 0.55, suggesting their price drivers have been diverging.

Return for Risk

BTTRX vs. RFBAX — Risk / Return Rank

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

RFBAX

RFBAX Risk / Return Rank: 69
RFBAX Sharpe Ratio Rank: 40
RFBAX Sortino Ratio Rank: 51
RFBAX Omega Ratio Rank: 77
RFBAX Calmar Ratio Rank: 89
RFBAX Martin Ratio Rank: 89

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.

BTTRX vs. RFBAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Zero Coupon 2025 Fund (BTTRX) and Davis Government Bond Fund (RFBAX). 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.

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

Sharpe Ratios by Period

	BTTRX	RFBAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	—	1.86	—
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.62	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.61	—
Sharpe Ratio (All Time) Calculated using the full available price history	—	1.05	—

Drawdowns

Drawdown Indicators

	BTTRX	RFBAX	Difference
Max Drawdown Largest peak-to-trough decline	—	-8.03%	—
Max Drawdown (1Y) Largest decline over 1 year	—	-0.77%	—
Max Drawdown (3Y) Largest decline over 3 years	—	-0.88%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-7.61%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-8.03%	—
Current Drawdown Current decline from peak	—	-0.19%	—
Average Drawdown Average peak-to-trough decline	—	-1.18%	—
Ulcer Index Depth and duration of drawdowns from previous peaks	—	0.19%	—

Volatility

Volatility by Period

	BTTRX	RFBAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	—	0.59%	—
Volatility (6M) Calculated over the trailing 6-month period	—	1.26%	—
Volatility (1Y) Calculated over the trailing 1-year period	—	1.89%	—
Volatility (5Y) Calculated over the trailing 5-year period, annualized	—	2.10%	—
Volatility (10Y) Calculated over the trailing 10-year period, annualized	—	1.79%	—

BTTRX vs. RFBAX - Expense Ratio Comparison

BTTRX has a 0.54% expense ratio, which is lower than RFBAX's 1.00% expense ratio.

Dividends

BTTRX vs. RFBAX - Dividend Comparison

BTTRX has not paid dividends to shareholders, while RFBAX's dividend yield for the trailing twelve months is around 3.04%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BTTRX American Century Zero Coupon 2025 Fund	0.00%	0.00%	4.96%	4.00%	3.47%	3.27%	7.69%	3.90%	5.25%	1.05%	3.42%	2.85%
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 BTTRX and RFBAX in my portfolio?

BTTRX and RFBAX have a correlation of 0.09, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.