DOXIX vs. SSFEX

Last updated Jun 3, 2026

DOXIX (Dodge & Cox Income Fund Class X) and SSFEX (State Street Aggregate Bond Index Fund Class K) are both mutual funds - DOXIX is a Intermediate Core-Plus Bond fund actively managed by Dodge & Cox, while SSFEX is a Total Bond Market fund managed by State Street. Over the past 3 years, DOXIX returned 5.31%/yr vs 3.88%/yr for SSFEX. With a 0.97 correlation, they move nearly in lockstep. DOXIX charges 0.33%/yr vs 0.03%/yr for SSFEX.

Performance

DOXIX vs. SSFEX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Dodge & Cox Income Fund Class X (DOXIX) and State Street Aggregate Bond Index Fund Class K (SSFEX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, DOXIX achieves a 0.45% return, which is significantly higher than SSFEX's 0.37% return.

DOXIX

• 1D: -0.08%
• 1M: 0.08%
• YTD: 0.45%
• 6M: 0.59%
• 1Y: 6.42%
• 3Y*: 5.31%
• 5Y*: —
• 10Y*: —

SSFEX

• 1D: -0.09%
• 1M: 0.11%
• YTD: 0.37%
• 6M: 0.42%
• 1Y: 5.32%
• 3Y*: 3.88%
• 5Y*: 0.06%
• 10Y*: -19.31%

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

DOXIX vs. SSFEX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022
DOXIX Dodge & Cox Income Fund Class X	0.45%	8.39%	2.33%	7.75%	-2.35%
SSFEX State Street Aggregate Bond Index Fund Class K	0.37%	6.80%	1.35%	5.61%	-3.54%

Correlation

The correlation between DOXIX and SSFEX is 0.97 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.97
Correlation (3Y) Calculated over the trailing 3-year period	0.97
Correlation (All Time) Calculated using the full available price history since May 4, 2022	0.97

The correlation between DOXIX and SSFEX has been stable across timeframes, ranging from 0.97 to 0.97 - a consistent structural relationship.

Return for Risk

DOXIX vs. SSFEX — Risk / Return Rank

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

DOXIX

DOXIX Risk / Return Rank: 28
DOXIX Sharpe Ratio Rank: 28
DOXIX Sortino Ratio Rank: 29
DOXIX Omega Ratio Rank: 27
DOXIX Calmar Ratio Rank: 28
DOXIX Martin Ratio Rank: 24

SSFEX

SSFEX Risk / Return Rank: 22
SSFEX Sharpe Ratio Rank: 22
SSFEX Sortino Ratio Rank: 23
SSFEX Omega Ratio Rank: 20
SSFEX Calmar Ratio Rank: 26
SSFEX Martin Ratio Rank: 22

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.

DOXIX vs. SSFEX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Dodge & Cox Income Fund Class X (DOXIX) and State Street Aggregate Bond Index Fund Class K (SSFEX). 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.

	DOXIX	SSFEX	Difference
Sharpe ratio Return per unit of total volatility	1.55	1.35	+0.20
Sortino ratio Return per unit of downside risk	2.29	2.02	+0.28
Omega ratio Gain probability vs. loss probability	1.28	1.24	+0.04
Calmar ratio Return relative to maximum drawdown	2.04	1.91	+0.13
Martin ratio Return relative to average drawdown	6.32	5.88	+0.44
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

DOXIX vs. SSFEX - Sharpe Ratio Comparison

The current DOXIX Sharpe Ratio is 1.55, which is comparable to the SSFEX Sharpe Ratio of 1.35. The chart below compares the historical Sharpe Ratios of DOXIX and SSFEX, 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

	DOXIX	SSFEX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.55	1.35	+0.20
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.01	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	-0.61	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.68	-0.55	+1.24

Drawdowns

DOXIX vs. SSFEX - Drawdown Comparison

The maximum DOXIX drawdown since its inception was -8.83%, smaller than the maximum SSFEX drawdown of -92.70%. Use the drawdown chart below to compare losses from any high point for DOXIX and SSFEX.

Drawdown Indicators

	DOXIX	SSFEX	Difference
Max Drawdown Largest peak-to-trough decline	-8.83%	-92.70%	+83.87%
Max Drawdown (1Y) Largest decline over 1 year	-3.15%	-2.75%	-0.40%
Max Drawdown (3Y) Largest decline over 3 years	-5.66%	-6.09%	+0.43%
Max Drawdown (5Y) Largest decline over 5 years	—	-17.99%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-92.70%	—
Current Drawdown Current decline from peak	-1.69%	-90.06%	+88.37%
Average Drawdown Average peak-to-trough decline	-1.86%	-47.98%	+46.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.02%	0.89%	+0.13%

Volatility

DOXIX vs. SSFEX - Volatility Comparison

Dodge & Cox Income Fund Class X (DOXIX) has a higher volatility of 1.42% compared to State Street Aggregate Bond Index Fund Class K (SSFEX) at 1.30%. This indicates that DOXIX's price experiences larger fluctuations and is considered to be riskier than SSFEX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	DOXIX	SSFEX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.42%	1.30%	+0.12%
Volatility (6M) Calculated over the trailing 6-month period	2.94%	2.66%	+0.28%
Volatility (1Y) Calculated over the trailing 1-year period	4.06%	3.75%	+0.31%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.86%	5.93%	-0.07%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.86%	31.84%	-25.98%

DOXIX vs. SSFEX - Expense Ratio Comparison

DOXIX has a 0.33% expense ratio, which is higher than SSFEX's 0.03% expense ratio.

Dividends

DOXIX vs. SSFEX - Dividend Comparison

DOXIX's dividend yield for the trailing twelve months is around 4.33%, more than SSFEX's 4.08% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
DOXIX Dodge & Cox Income Fund Class X	4.33%	4.30%	4.32%	3.92%	2.30%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
SSFEX State Street Aggregate Bond Index Fund Class K	4.08%	3.66%	3.76%	3.14%	2.48%	3.32%	9.59%	3.56%	2.79%	2.43%	2.19%	4.67%

Frequently Asked Questions

Can I hold both DOXIX and SSFEX in my portfolio?

With a correlation of 0.97, DOXIX and SSFEX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, DOXIX or SSFEX?

DOXIX has higher volatility (1.42%) compared to SSFEX (1.30%). In terms of maximum drawdown, DOXIX dropped -8.83% vs SSFEX's -92.70%.

Which has better risk-adjusted returns?

DOXIX currently has the higher Sharpe Ratio (1.55 vs 1.35), 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.