DOXIX vs. FIFZX

Last updated Jun 23, 2026

DOXIX (Dodge & Cox Income Fund Class X) and FIFZX (Fidelity Series Bond Index Fund) are both mutual funds - DOXIX is a Intermediate Core-Plus Bond fund actively managed by Dodge & Cox, while FIFZX is a Total Bond Market fund managed by Fidelity. Over the past 3 years, DOXIX returned 5.28%/yr vs 4.06%/yr for FIFZX. With a 0.96 correlation, they move nearly in lockstep. DOXIX charges 0.33%/yr vs 0.00%/yr for FIFZX.

Performance

DOXIX vs. FIFZX - Performance Comparison

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

Returns By Period

In the year-to-date period, DOXIX achieves a 0.69% return, which is significantly higher than FIFZX's 0.45% return.

DOXIX

• 1D: 0.23%
• 1M: 0.95%
• YTD: 0.69%
• 6M: 0.85%
• 1Y: 5.82%
• 3Y*: 5.28%
• 5Y*: —
• 10Y*: —

FIFZX

• 1D: 0.22%
• 1M: 0.91%
• YTD: 0.45%
• 6M: 0.79%
• 1Y: 4.75%
• 3Y*: 4.06%
• 5Y*: -0.07%
• 10Y*: —

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

DOXIX vs. FIFZX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022
DOXIX Dodge & Cox Income Fund Class X	0.69%	8.39%	2.33%	7.75%	-2.35%
FIFZX Fidelity Series Bond Index Fund	0.45%	7.15%	1.41%	5.54%	-3.94%

Correlation

The correlation between DOXIX and FIFZX is 0.93, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.93
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (All Time) Calculated using the full available price history since May 3, 2022	0.96

The correlation between DOXIX and FIFZX has been stable across timeframes, ranging from 0.93 to 0.96 - a consistent structural relationship.

Return for Risk

DOXIX vs. FIFZX — 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: 30
DOXIX Sortino Ratio Rank: 31
DOXIX Omega Ratio Rank: 29
DOXIX Calmar Ratio Rank: 28
DOXIX Martin Ratio Rank: 24

FIFZX

FIFZX Risk / Return Rank: 22
FIFZX Sharpe Ratio Rank: 22
FIFZX Sortino Ratio Rank: 24
FIFZX Omega Ratio Rank: 20
FIFZX Calmar Ratio Rank: 23
FIFZX Martin Ratio Rank: 20

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. FIFZX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Dodge & Cox Income Fund Class X (DOXIX) and Fidelity Series Bond Index Fund (FIFZX). 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.

	DOXIX	FIFZX	Difference
Sharpe ratio: Return per unit of total volatility	1.46	1.25	+0.21
Sortino ratio: Return per unit of downside risk	2.16	1.90	+0.26
Omega ratio: Gain probability vs. loss probability	1.26	1.22	+0.04
Calmar ratio: Return relative to maximum drawdown	1.86	1.68	+0.18
Martin ratio: Return relative to average drawdown	5.37	4.75	+0.62

DOXIX vs. FIFZX - Sharpe Ratio Comparison

The current DOXIX Sharpe Ratio is 1.46, which is comparable to the FIFZX Sharpe Ratio of 1.25. The chart below compares the historical Sharpe Ratios of DOXIX and FIFZX, 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

DOXIX vs. FIFZX - Drawdown Comparison

The maximum DOXIX drawdown since its inception was -8.83%, smaller than the maximum FIFZX drawdown of -19.27%. Use the drawdown chart below to compare losses from any high point for DOXIX and FIFZX.

Drawdown Indicators

	DOXIX	FIFZX	Difference
Max Drawdown Largest peak-to-trough decline	-8.83%	-19.27%	+10.44%
Max Drawdown (1Y) Largest decline over 1 year	-3.15%	-2.91%	-0.24%
Max Drawdown (3Y) Largest decline over 3 years	-5.66%	-6.12%	+0.46%
Max Drawdown (5Y) Largest decline over 5 years	—	-18.47%	—
Current Drawdown Current decline from peak	-1.46%	-2.75%	+1.29%
Average Drawdown Average peak-to-trough decline	-1.86%	-6.67%	+4.81%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.09%	1.03%	+0.06%

Volatility

DOXIX vs. FIFZX - Volatility Comparison

Dodge & Cox Income Fund Class X (DOXIX) and Fidelity Series Bond Index Fund (FIFZX) have volatilities of 1.25% and 1.22%, 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

	DOXIX	FIFZX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.25%	1.22%	+0.03%
Volatility (6M) Calculated over the trailing 6-month period	3.01%	2.88%	+0.13%
Volatility (1Y) Calculated over the trailing 1-year period	4.00%	3.92%	+0.08%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.84%	6.08%	-0.24%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.84%	5.62%	+0.22%

DOXIX vs. FIFZX - Expense Ratio Comparison

DOXIX has a 0.33% expense ratio, which is higher than FIFZX's 0.00% expense ratio.

Dividends

DOXIX vs. FIFZX - Dividend Comparison

DOXIX's dividend yield for the trailing twelve months is around 4.32%, more than FIFZX's 4.00% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019
DOXIX Dodge & Cox Income Fund Class X	4.32%	4.30%	4.32%	3.92%	2.30%	0.00%	0.00%	0.00%
FIFZX Fidelity Series Bond Index Fund	4.00%	3.87%	3.66%	3.09%	1.74%	1.42%	3.20%	1.64%

Frequently Asked Questions

Can I hold both DOXIX and FIFZX in my portfolio?

With a correlation of 0.93, DOXIX and FIFZX 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 FIFZX?

DOXIX has higher volatility (1.25%) compared to FIFZX (1.22%). In terms of maximum drawdown, DOXIX dropped -8.83% vs FIFZX's -19.27%.

Which has better risk-adjusted returns?

DOXIX currently has the higher Sharpe Ratio (1.46 vs 1.25), 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.