FMSFX vs. VBIMX

Last updated Jun 24, 2026

FMSFX (Fidelity Mortgage Securities Fund) and VBIMX (Vanguard Intermediate-Term Bond Index Fund Institutional Shares) are both Total Bond Market funds. Over the past 10 years, FMSFX returned 1.25%/yr vs 1.79%/yr for VBIMX. Their correlation of 0.84 suggests significant overlap in exposure. FMSFX charges 0.45%/yr vs 0.05%/yr for VBIMX.

Performance

FMSFX vs. VBIMX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Mortgage Securities Fund (FMSFX) and Vanguard Intermediate-Term Bond Index Fund Institutional Shares (VBIMX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FMSFX achieves a 0.66% return, which is significantly higher than VBIMX's -0.52% return. Over the past 10 years, FMSFX has underperformed VBIMX with an annualized return of 1.25%, while VBIMX has yielded a comparatively higher 1.79% annualized return.

FMSFX

• 1D: -0.20%
• 1M: 0.63%
• YTD: 0.66%
• 6M: 0.97%
• 1Y: 5.80%
• 3Y*: 4.25%
• 5Y*: 0.14%
• 10Y*: 1.25%

VBIMX

• 1D: -0.29%
• 1M: 0.47%
• YTD: -0.52%
• 6M: -0.07%
• 1Y: 3.78%
• 3Y*: 4.25%
• 5Y*: 0.12%
• 10Y*: 1.79%

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

FMSFX vs. VBIMX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FMSFX Fidelity Mortgage Securities Fund	0.66%	8.29%	1.00%	4.91%	-12.61%	-1.20%	4.41%	6.43%	0.79%	2.35%
VBIMX Vanguard Intermediate-Term Bond Index Fund Institutional Shares	-0.52%	8.59%	1.55%	5.78%	-13.25%	-2.50%	9.83%	10.22%	-0.13%	3.89%

Correlation

The correlation between FMSFX and VBIMX is 0.94, 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	0.94
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	0.88
Correlation (All Time) Calculated using the full available price history since Jan 26, 2006	0.84

The correlation between FMSFX and VBIMX shifts across timeframes, from 0.84 (all time) to 0.95 (3 years), reflecting how their relationship changes across market environments.

Return for Risk

FMSFX vs. VBIMX — Risk / Return Rank

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

FMSFX

FMSFX Risk / Return Rank: 34
FMSFX Sharpe Ratio Rank: 33
FMSFX Sortino Ratio Rank: 35
FMSFX Omega Ratio Rank: 32
FMSFX Calmar Ratio Rank: 36
FMSFX Martin Ratio Rank: 31

VBIMX

VBIMX Risk / Return Rank: 14
VBIMX Sharpe Ratio Rank: 14
VBIMX Sortino Ratio Rank: 15
VBIMX Omega Ratio Rank: 13
VBIMX Calmar Ratio Rank: 14
VBIMX Martin Ratio Rank: 12

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. VBIMX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mortgage Securities Fund (FMSFX) and Vanguard Intermediate-Term Bond Index Fund Institutional Shares (VBIMX). 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.

	FMSFX	VBIMX	Difference
Sharpe ratio: Return per unit of total volatility	1.54	0.99	+0.55
Sortino ratio: Return per unit of downside risk	2.31	1.49	+0.82
Omega ratio: Gain probability vs. loss probability	1.28	1.17	+0.11
Calmar ratio: Return relative to maximum drawdown	2.15	1.20	+0.95
Martin ratio: Return relative to average drawdown	6.71	3.33	+3.38

FMSFX vs. VBIMX - Sharpe Ratio Comparison

The current FMSFX Sharpe Ratio is 1.54, which is higher than the VBIMX Sharpe Ratio of 0.99. The chart below compares the historical Sharpe Ratios of FMSFX and VBIMX, 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

FMSFX vs. VBIMX - Drawdown Comparison

The maximum FMSFX drawdown since its inception was -18.81%, roughly equal to the maximum VBIMX drawdown of -19.07%. Use the drawdown chart below to compare losses from any high point for FMSFX and VBIMX.

Drawdown Indicators

	FMSFX	VBIMX	Difference
Max Drawdown Largest peak-to-trough decline	-18.81%	-19.07%	+0.26%
Max Drawdown (1Y) Largest decline over 1 year	-2.81%	-3.42%	+0.61%
Max Drawdown (3Y) Largest decline over 3 years	-8.04%	-6.05%	-1.99%
Max Drawdown (5Y) Largest decline over 5 years	-18.66%	-18.84%	+0.18%
Max Drawdown (10Y) Largest decline over 10 years	-18.81%	-19.07%	+0.26%
Current Drawdown Current decline from peak	-1.41%	-2.30%	+0.89%
Average Drawdown Average peak-to-trough decline	-1.92%	-3.32%	+1.40%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.90%	1.23%	-0.33%

Volatility

FMSFX vs. VBIMX - Volatility Comparison

The current volatility for Fidelity Mortgage Securities Fund (FMSFX) is 1.23%, while Vanguard Intermediate-Term Bond Index Fund Institutional Shares (VBIMX) has a volatility of 1.33%. This indicates that FMSFX experiences smaller price fluctuations and is considered to be less risky than VBIMX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FMSFX	VBIMX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.23%	1.33%	-0.10%
Volatility (6M) Calculated over the trailing 6-month period	2.90%	3.13%	-0.23%
Volatility (1Y) Calculated over the trailing 1-year period	3.94%	4.16%	-0.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.80%	6.39%	+0.41%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.14%	5.39%	-0.25%

FMSFX vs. VBIMX - Expense Ratio Comparison

FMSFX has a 0.45% expense ratio, which is higher than VBIMX's 0.05% expense ratio.

Dividends

FMSFX vs. VBIMX - Dividend Comparison

FMSFX's dividend yield for the trailing twelve months is around 3.92%, less than VBIMX's 4.25% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FMSFX Fidelity Mortgage Securities Fund	3.92%	3.93%	4.12%	3.50%	1.43%	0.62%	2.40%	2.62%	2.57%	2.60%	2.65%	2.05%
VBIMX Vanguard Intermediate-Term Bond Index Fund Institutional Shares	4.25%	4.03%	3.82%	2.82%	2.41%	3.23%	2.95%	2.75%	2.89%	2.76%	3.08%	3.12%

Frequently Asked Questions

Can I hold both FMSFX and VBIMX in my portfolio?

With a correlation of 0.94, FMSFX and VBIMX 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 VBIMX?

VBIMX has higher volatility (1.33%) compared to FMSFX (1.23%). In terms of maximum drawdown, FMSFX dropped -18.81% vs VBIMX's -19.07%.

Which has better risk-adjusted returns?

FMSFX currently has the higher Sharpe Ratio (1.54 vs 0.99), 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.