FSMDX vs. FXNAX

Last updated Jun 13, 2026

FSMDX (Fidelity Mid Cap Index Fund) and FXNAX (Fidelity U.S. Bond Index Fund) are both mutual funds - FSMDX is a Mid Cap Blend Equities fund tracking the Russell Midcap Index, while FXNAX is a Total Bond Market fund tracking the Bloomberg U.S. Aggregate Bond Index. Both are passively managed. Over the past 10 years, FSMDX returned 11.76%/yr vs 1.48%/yr for FXNAX. At a correlation of -0.09, they often move in opposite directions. Both charge a 0.03% expense ratio.

Performance

FSMDX vs. FXNAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Mid Cap Index Fund (FSMDX) and Fidelity U.S. Bond Index Fund (FXNAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FSMDX achieves a 12.29% return, which is significantly higher than FXNAX's 0.50% return. Over the past 10 years, FSMDX has outperformed FXNAX with an annualized return of 11.76%, while FXNAX has yielded a comparatively lower 1.48% annualized return.

FSMDX

• 1D: 2.24%
• 1M: 2.47%
• YTD: 12.29%
• 6M: 11.02%
• 1Y: 22.43%
• 3Y*: 16.72%
• 5Y*: 8.00%
• 10Y*: 11.76%

FXNAX

• 1D: 0.58%
• 1M: 0.61%
• YTD: 0.50%
• 6M: 1.01%
• 1Y: 4.96%
• 3Y*: 4.05%
• 5Y*: -0.02%
• 10Y*: 1.48%

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

FSMDX vs. FXNAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FSMDX Fidelity Mid Cap Index Fund	12.29%	10.58%	15.55%	17.20%	-17.27%	22.56%	17.13%	30.53%	-9.38%	18.04%
FXNAX Fidelity U.S. Bond Index Fund	0.50%	7.14%	1.35%	5.82%	-13.55%	-2.10%	7.63%	8.50%	0.04%	3.50%

Correlation

The correlation between FSMDX and FXNAX is 0.33, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.33
Correlation (3Y) Calculated over the trailing 3-year period	0.25
Correlation (5Y) Calculated over the trailing 5-year period	0.16
Correlation (10Y) Calculated over the trailing 10-year period	0.01
Correlation (All Time) Calculated using the full available price history since Sep 9, 2011	-0.09

The correlation between FSMDX and FXNAX shifts across timeframes, from -0.09 (all time) to 0.33 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

FSMDX vs. FXNAX — Risk / Return Rank

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

FSMDX

FSMDX Risk / Return Rank: 52
FSMDX Sharpe Ratio Rank: 44
FSMDX Sortino Ratio Rank: 45
FSMDX Omega Ratio Rank: 40
FSMDX Calmar Ratio Rank: 68
FSMDX Martin Ratio Rank: 64

FXNAX

FXNAX Risk / Return Rank: 30
FXNAX Sharpe Ratio Rank: 31
FXNAX Sortino Ratio Rank: 34
FXNAX Omega Ratio Rank: 30
FXNAX Calmar Ratio Rank: 31
FXNAX Martin Ratio Rank: 26

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.

FSMDX vs. FXNAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mid Cap Index Fund (FSMDX) and Fidelity U.S. Bond Index Fund (FXNAX). 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.

	FSMDX	FXNAX	Difference
Sharpe ratio: Return per unit of total volatility	1.53	1.27	+0.26
Sortino ratio: Return per unit of downside risk	2.20	1.93	+0.28
Omega ratio: Gain probability vs. loss probability	1.27	1.23	+0.04
Calmar ratio: Return relative to maximum drawdown	2.58	1.69	+0.89
Martin ratio: Return relative to average drawdown	9.88	4.97	+4.90

FSMDX vs. FXNAX - Sharpe Ratio Comparison

The current FSMDX Sharpe Ratio is 1.53, which is comparable to the FXNAX Sharpe Ratio of 1.27. The chart below compares the historical Sharpe Ratios of FSMDX and FXNAX, 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

FSMDX vs. FXNAX - Drawdown Comparison

The maximum FSMDX drawdown since its inception was -40.35%, which is greater than FXNAX's maximum drawdown of -19.51%. Use the drawdown chart below to compare losses from any high point for FSMDX and FXNAX.

Drawdown Indicators

	FSMDX	FXNAX	Difference
Max Drawdown Largest peak-to-trough decline	-40.35%	-19.51%	-20.84%
Max Drawdown (1Y) Largest decline over 1 year	-8.16%	-2.94%	-5.22%
Max Drawdown (3Y) Largest decline over 3 years	-20.92%	-6.16%	-14.76%
Max Drawdown (5Y) Largest decline over 5 years	-26.07%	-18.54%	-7.53%
Max Drawdown (10Y) Largest decline over 10 years	-40.35%	-19.51%	-20.84%
Current Drawdown Current decline from peak	-0.67%	-2.79%	+2.12%
Average Drawdown Average peak-to-trough decline	-4.95%	-3.86%	-1.09%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.13%	1.00%	+1.13%

Volatility

FSMDX vs. FXNAX - Volatility Comparison

Fidelity Mid Cap Index Fund (FSMDX) has a higher volatility of 4.48% compared to Fidelity U.S. Bond Index Fund (FXNAX) at 1.41%. This indicates that FSMDX's price experiences larger fluctuations and is considered to be riskier than FXNAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FSMDX	FXNAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.48%	1.41%	+3.07%
Volatility (6M) Calculated over the trailing 6-month period	10.46%	2.87%	+7.59%
Volatility (1Y) Calculated over the trailing 1-year period	13.80%	3.93%	+9.87%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.32%	6.08%	+12.24%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	19.34%	5.01%	+14.33%

FSMDX vs. FXNAX - Expense Ratio Comparison

Both FSMDX and FXNAX have an expense ratio of 0.03%, making them cost-effective options compared to the broader market, where average expense ratios typically range from 0.3% to 0.9%.

Dividends

FSMDX vs. FXNAX - Dividend Comparison

FSMDX's dividend yield for the trailing twelve months is around 0.98%, less than FXNAX's 3.70% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSMDX Fidelity Mid Cap Index Fund	0.98%	1.10%	2.46%	1.39%	2.07%	3.35%	2.34%	2.86%	2.21%	2.17%	2.23%	2.84%
FXNAX Fidelity U.S. Bond Index Fund	3.70%	3.58%	3.40%	3.15%	1.81%	1.74%	2.92%	2.68%	2.74%	2.57%	2.76%	2.52%

Frequently Asked Questions

Can I hold both FSMDX and FXNAX in my portfolio?

FSMDX and FXNAX have a correlation of 0.33, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FSMDX or FXNAX?

FSMDX has higher volatility (4.48%) compared to FXNAX (1.41%). In terms of maximum drawdown, FSMDX dropped -40.35% vs FXNAX's -19.51%.

Which has better risk-adjusted returns?

FSMDX currently has the higher Sharpe Ratio (1.53 vs 1.27), 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.