FMSFX vs. VTBNX

Last updated Jun 5, 2026

FMSFX (Fidelity Mortgage Securities Fund) and VTBNX (Vanguard Total Bond Market II Index Fund) are both Total Bond Market funds. Over the past 10 years, FMSFX returned 1.28%/yr vs 1.53%/yr for VTBNX. Their correlation of 0.88 suggests significant overlap in exposure. FMSFX charges 0.45%/yr vs 0.02%/yr for VTBNX.

Performance

FMSFX vs. VTBNX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Mortgage Securities Fund (FMSFX) and Vanguard Total Bond Market II Index Fund (VTBNX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FMSFX achieves a 0.77% return, which is significantly higher than VTBNX's 0.12% return. Over the past 10 years, FMSFX has underperformed VTBNX with an annualized return of 1.28%, while VTBNX has yielded a comparatively higher 1.53% annualized return.

FMSFX

• 1D: -0.20%
• 1M: 0.12%
• YTD: 0.77%
• 6M: 1.07%
• 1Y: 6.12%
• 3Y*: 4.39%
• 5Y*: 0.14%
• 10Y*: 1.28%

VTBNX

• 1D: -0.21%
• 1M: 0.14%
• YTD: 0.12%
• 6M: 0.25%
• 1Y: 4.44%
• 3Y*: 3.94%
• 5Y*: 0.09%
• 10Y*: 1.53%

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

FMSFX vs. VTBNX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FMSFX Fidelity Mortgage Securities Fund	0.77%	8.29%	1.00%	4.91%	-12.61%	-1.20%	4.41%	6.43%	0.79%	2.35%
VTBNX Vanguard Total Bond Market II Index Fund	0.12%	7.18%	1.32%	5.68%	-13.12%	-1.82%	7.39%	8.71%	-0.27%	3.62%

Correlation

The correlation between FMSFX and VTBNX is 0.95 - 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	0.95
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.93
Correlation (10Y) Calculated over the trailing 10-year period	0.89
Correlation (All Time) Calculated using the full available price history since Jan 25, 2016	0.88

The correlation between FMSFX and VTBNX has been stable across timeframes, ranging from 0.88 to 0.95 - a consistent structural relationship.

Return for Risk

FMSFX vs. VTBNX — Risk / Return Rank

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

FMSFX

FMSFX Risk / Return Rank: 37
FMSFX Sharpe Ratio Rank: 36
FMSFX Sortino Ratio Rank: 38
FMSFX Omega Ratio Rank: 35
FMSFX Calmar Ratio Rank: 41
FMSFX Martin Ratio Rank: 37

VTBNX

VTBNX Risk / Return Rank: 21
VTBNX Sharpe Ratio Rank: 20
VTBNX Sortino Ratio Rank: 22
VTBNX Omega Ratio Rank: 18
VTBNX Calmar Ratio Rank: 23
VTBNX 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.

FMSFX vs. VTBNX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mortgage Securities Fund (FMSFX) and Vanguard Total Bond Market II Index Fund (VTBNX). 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.

	FMSFX	VTBNX	Difference
Sharpe ratio: Return per unit of total volatility	1.71	1.28	+0.43
Sortino ratio: Return per unit of downside risk	2.57	1.94	+0.64
Omega ratio: Gain probability vs. loss probability	1.31	1.22	+0.09
Calmar ratio: Return relative to maximum drawdown	2.42	1.77	+0.65
Martin ratio: Return relative to average drawdown	7.96	5.27	+2.69
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FMSFX vs. VTBNX - Sharpe Ratio Comparison

The current FMSFX Sharpe Ratio is 1.71, which is higher than the VTBNX Sharpe Ratio of 1.28. The chart below compares the historical Sharpe Ratios of FMSFX and VTBNX, 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

	FMSFX	VTBNX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.71	1.28	+0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.02	0.02	+0.01
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.25	0.31	-0.06
Sharpe Ratio (All Time) Calculated using the full available price history	1.02	0.37	+0.65

Drawdowns

FMSFX vs. VTBNX - Drawdown Comparison

The maximum FMSFX drawdown since its inception was -18.81%, roughly equal to the maximum VTBNX drawdown of -18.71%. Use the drawdown chart below to compare losses from any high point for FMSFX and VTBNX.

Drawdown Indicators

	FMSFX	VTBNX	Difference
Max Drawdown Largest peak-to-trough decline	-18.81%	-18.71%	-0.10%
Max Drawdown (1Y) Largest decline over 1 year	-2.81%	-2.83%	+0.02%
Max Drawdown (3Y) Largest decline over 3 years	-8.04%	-5.97%	-2.07%
Max Drawdown (5Y) Largest decline over 5 years	-18.66%	-18.05%	-0.61%
Max Drawdown (10Y) Largest decline over 10 years	-18.81%	-18.71%	-0.10%
Current Drawdown Current decline from peak	-1.31%	-2.41%	+1.10%
Average Drawdown Average peak-to-trough decline	-1.92%	-4.87%	+2.95%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.85%	0.95%	-0.10%

Volatility

FMSFX vs. VTBNX - Volatility Comparison

Fidelity Mortgage Securities Fund (FMSFX) has a higher volatility of 1.45% compared to Vanguard Total Bond Market II Index Fund (VTBNX) at 1.31%. This indicates that FMSFX's price experiences larger fluctuations and is considered to be riskier than VTBNX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FMSFX	VTBNX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.45%	1.31%	+0.14%
Volatility (6M) Calculated over the trailing 6-month period	2.79%	2.78%	+0.01%
Volatility (1Y) Calculated over the trailing 1-year period	3.99%	3.92%	+0.07%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.79%	5.96%	+0.83%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.13%	4.93%	+0.20%

FMSFX vs. VTBNX - Expense Ratio Comparison

FMSFX has a 0.45% expense ratio, which is higher than VTBNX's 0.02% expense ratio.

Dividends

FMSFX vs. VTBNX - Dividend Comparison

FMSFX's dividend yield for the trailing twelve months is around 3.91%, less than VTBNX's 4.06% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FMSFX Fidelity Mortgage Securities Fund	3.91%	3.93%	4.12%	3.50%	1.43%	0.62%	2.40%	2.62%	2.57%	2.60%	2.65%	2.05%
VTBNX Vanguard Total Bond Market II Index Fund	4.06%	3.95%	3.77%	3.13%	2.54%	1.82%	3.12%	2.79%	2.56%	2.52%	2.55%	0.00%

Frequently Asked Questions

Can I hold both FMSFX and VTBNX in my portfolio?

With a correlation of 0.95, FMSFX and VTBNX 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, FMSFX or VTBNX?

FMSFX has higher volatility (1.45%) compared to VTBNX (1.31%). In terms of maximum drawdown, FMSFX dropped -18.81% vs VTBNX's -18.71%.

Which has better risk-adjusted returns?

FMSFX currently has the higher Sharpe Ratio (1.71 vs 1.28), 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.