TWUSX vs. DFFGX

Last updated Jun 4, 2026

TWUSX (American Century Short-Term Government Fund) and DFFGX (DFA Short-Term Government Portfolio) are both Government Bonds funds. Over the past 10 years, TWUSX returned 1.51%/yr vs 1.23%/yr for DFFGX. At a 0.49 correlation, their price movements are largely independent. TWUSX charges 0.55%/yr vs 0.18%/yr for DFFGX.

Performance

TWUSX vs. DFFGX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in American Century Short-Term Government Fund (TWUSX) and DFA Short-Term Government Portfolio (DFFGX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TWUSX achieves a 0.36% return, which is significantly lower than DFFGX's 1.38% return. Over the past 10 years, TWUSX has outperformed DFFGX with an annualized return of 1.51%, while DFFGX has yielded a comparatively lower 1.23% annualized return.

TWUSX

• 1D: -0.11%
• 1M: 0.10%
• YTD: 0.36%
• 6M: 0.66%
• 1Y: 3.30%
• 3Y*: 3.83%
• 5Y*: 1.48%
• 10Y*: 1.51%

DFFGX

• 1D: 0.00%
• 1M: 0.20%
• YTD: 1.38%
• 6M: 1.72%
• 1Y: 2.79%
• 3Y*: 4.29%
• 5Y*: 1.83%
• 10Y*: 1.23%

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

TWUSX vs. DFFGX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TWUSX American Century Short-Term Government Fund	0.36%	4.94%	3.59%	3.70%	-4.31%	-0.09%	3.36%	2.91%	1.12%	0.22%
DFFGX DFA Short-Term Government Portfolio	1.38%	3.12%	5.29%	5.01%	-4.41%	-1.27%	0.39%	2.52%	1.17%	0.51%

Correlation

The correlation between TWUSX and DFFGX is 0.16, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.16
Correlation (3Y) Calculated over the trailing 3-year period	0.06
Correlation (5Y) Calculated over the trailing 5-year period	0.30
Correlation (10Y) Calculated over the trailing 10-year period	0.33
Correlation (All Time) Calculated using the full available price history since May 14, 1987	0.49

Over the past year, the correlation between TWUSX and DFFGX has dropped to 0.16 - well below their long-term average of 0.49, suggesting their price drivers have been diverging.

Return for Risk

TWUSX vs. DFFGX — Risk / Return Rank

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

TWUSX

TWUSX Risk / Return Rank: 58
TWUSX Sharpe Ratio Rank: 40
TWUSX Sortino Ratio Rank: 61
TWUSX Omega Ratio Rank: 54
TWUSX Calmar Ratio Rank: 75
TWUSX Martin Ratio Rank: 60

DFFGX

DFFGX Risk / Return Rank: 62
DFFGX Sharpe Ratio Rank: 63
DFFGX Sortino Ratio Rank: 41
DFFGX Omega Ratio Rank: 99
DFFGX Calmar Ratio Rank: 55
DFFGX Martin Ratio Rank: 52

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.

TWUSX vs. DFFGX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for American Century Short-Term Government Fund (TWUSX) and DFA Short-Term Government Portfolio (DFFGX). 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.

	TWUSX	DFFGX	Difference
Sharpe ratio: Return per unit of total volatility	1.84	2.33	-0.49
Sortino ratio: Return per unit of downside risk	3.29	2.70	+0.58
Omega ratio: Gain probability vs. loss probability	1.41	2.73	-1.32
Calmar ratio: Return relative to maximum drawdown	3.39	2.83	+0.55
Martin ratio: Return relative to average drawdown	11.83	10.57	+1.26
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TWUSX vs. DFFGX - Sharpe Ratio Comparison

The current TWUSX Sharpe Ratio is 1.84, which is comparable to the DFFGX Sharpe Ratio of 2.33. The chart below compares the historical Sharpe Ratios of TWUSX and DFFGX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	TWUSX	DFFGX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.84	2.33	-0.49
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.65	1.00	-0.36
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.83	0.79	+0.04
Sharpe Ratio (All Time) Calculated using the full available price history	-0.00	0.21	-0.21

Drawdowns

TWUSX vs. DFFGX - Drawdown Comparison

The maximum TWUSX drawdown since its inception was -91.06%, which is greater than DFFGX's maximum drawdown of -6.49%. Use the drawdown chart below to compare losses from any high point for TWUSX and DFFGX.

Drawdown Indicators

	TWUSX	DFFGX	Difference
Max Drawdown Largest peak-to-trough decline	-91.06%	-6.49%	-84.57%
Max Drawdown (1Y) Largest decline over 1 year	-0.98%	-1.00%	+0.02%
Max Drawdown (3Y) Largest decline over 3 years	-1.09%	-1.19%	+0.10%
Max Drawdown (5Y) Largest decline over 5 years	-5.81%	-6.49%	+0.68%
Max Drawdown (10Y) Largest decline over 10 years	-5.85%	-6.49%	+0.64%
Current Drawdown Current decline from peak	-64.62%	-0.10%	-64.52%
Average Drawdown Average peak-to-trough decline	-76.98%	-0.77%	-76.21%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.28%	0.27%	+0.01%

Volatility

TWUSX vs. DFFGX - Volatility Comparison

American Century Short-Term Government Fund (TWUSX) has a higher volatility of 0.55% compared to DFA Short-Term Government Portfolio (DFFGX) at 0.35%. This indicates that TWUSX's price experiences larger fluctuations and is considered to be riskier than DFFGX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TWUSX	DFFGX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.55%	0.35%	+0.20%
Volatility (6M) Calculated over the trailing 6-month period	1.24%	0.52%	+0.72%
Volatility (1Y) Calculated over the trailing 1-year period	1.81%	1.21%	+0.60%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.31%	1.84%	+0.47%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.82%	1.56%	+0.26%

TWUSX vs. DFFGX - Expense Ratio Comparison

TWUSX has a 0.55% expense ratio, which is higher than DFFGX's 0.18% expense ratio.

Dividends

TWUSX vs. DFFGX - Dividend Comparison

TWUSX's dividend yield for the trailing twelve months is around 3.60%, more than DFFGX's 2.84% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
DFFGX DFA Short-Term Government Portfolio	2.84%	2.98%	4.87%	3.57%	1.85%	0.15%	0.29%	1.83%	1.53%	1.18%	0.99%	1.27%
TWUSX American Century Short-Term Government Fund	3.60%	3.70%	4.06%	3.83%	1.12%	1.05%	0.72%	1.81%	1.74%	1.06%	0.57%	0.53%

Frequently Asked Questions

Can I hold both TWUSX and DFFGX in my portfolio?

TWUSX and DFFGX have a correlation of 0.16, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TWUSX or DFFGX?

TWUSX has higher volatility (0.55%) compared to DFFGX (0.35%). In terms of maximum drawdown, TWUSX dropped -91.06% vs DFFGX's -6.49%.

Which has better risk-adjusted returns?

DFFGX currently has the higher Sharpe Ratio (2.33 vs 1.84), 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.