FMSFX vs. VBITX

Last updated Jun 24, 2026

FMSFX (Fidelity Mortgage Securities Fund) and VBITX (Vanguard Short-Term Bond Index Fund Institutional Shares) are both Total Bond Market funds. Over the past 10 years, FMSFX returned 1.25%/yr vs 1.83%/yr for VBITX. A 0.78 correlation means they provide meaningful diversification when combined. FMSFX charges 0.45%/yr vs 0.05%/yr for VBITX.

Performance

FMSFX vs. VBITX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Mortgage Securities Fund (FMSFX) and Vanguard Short-Term Bond Index Fund Institutional Shares (VBITX). 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 VBITX's -0.08% return. Over the past 10 years, FMSFX has underperformed VBITX with an annualized return of 1.25%, while VBITX has yielded a comparatively higher 1.83% 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%

VBITX

• 1D: -0.20%
• 1M: 0.15%
• YTD: -0.08%
• 6M: 0.35%
• 1Y: 3.05%
• 3Y*: 4.36%
• 5Y*: 1.52%
• 10Y*: 1.83%

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

FMSFX vs. VBITX - 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%
VBITX Vanguard Short-Term Bond Index Fund Institutional Shares	-0.08%	6.11%	3.77%	4.43%	-5.61%	-1.18%	4.72%	4.89%	1.38%	1.20%

Correlation

The correlation between FMSFX and VBITX is 0.86, 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	0.86
Correlation (3Y) Calculated over the trailing 3-year period	0.85
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (10Y) Calculated over the trailing 10-year period	0.80
Correlation (All Time) Calculated using the full available price history since Sep 27, 2011	0.78

The correlation between FMSFX and VBITX has been stable across timeframes, ranging from 0.78 to 0.86 - a consistent structural relationship.

Return for Risk

FMSFX vs. VBITX — 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

VBITX

VBITX Risk / Return Rank: 31
VBITX Sharpe Ratio Rank: 27
VBITX Sortino Ratio Rank: 35
VBITX Omega Ratio Rank: 30
VBITX Calmar Ratio Rank: 33
VBITX Martin Ratio Rank: 29

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. VBITX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Mortgage Securities Fund (FMSFX) and Vanguard Short-Term Bond Index Fund Institutional Shares (VBITX). 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	VBITX	Difference
Sharpe ratio: Return per unit of total volatility	1.54	1.38	+0.15
Sortino ratio: Return per unit of downside risk	2.31	2.30	+0.01
Omega ratio: Gain probability vs. loss probability	1.28	1.27	+0.01
Calmar ratio: Return relative to maximum drawdown	2.15	2.05	+0.10
Martin ratio: Return relative to average drawdown	6.71	6.32	+0.39

FMSFX vs. VBITX - Sharpe Ratio Comparison

The current FMSFX Sharpe Ratio is 1.54, which is comparable to the VBITX Sharpe Ratio of 1.38. The chart below compares the historical Sharpe Ratios of FMSFX and VBITX, 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. VBITX - Drawdown Comparison

The maximum FMSFX drawdown since its inception was -18.81%, which is greater than VBITX's maximum drawdown of -8.65%. Use the drawdown chart below to compare losses from any high point for FMSFX and VBITX.

Drawdown Indicators

	FMSFX	VBITX	Difference
Max Drawdown Largest peak-to-trough decline	-18.81%	-8.65%	-10.16%
Max Drawdown (1Y) Largest decline over 1 year	-2.81%	-1.54%	-1.27%
Max Drawdown (3Y) Largest decline over 3 years	-8.04%	-1.54%	-6.50%
Max Drawdown (5Y) Largest decline over 5 years	-18.66%	-8.61%	-10.05%
Max Drawdown (10Y) Largest decline over 10 years	-18.81%	-8.65%	-10.16%
Current Drawdown Current decline from peak	-1.41%	-1.01%	-0.40%
Average Drawdown Average peak-to-trough decline	-1.92%	-1.18%	-0.74%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.90%	0.50%	+0.40%

Volatility

FMSFX vs. VBITX - Volatility Comparison

Fidelity Mortgage Securities Fund (FMSFX) has a higher volatility of 1.23% compared to Vanguard Short-Term Bond Index Fund Institutional Shares (VBITX) at 0.72%. This indicates that FMSFX's price experiences larger fluctuations and is considered to be riskier than VBITX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FMSFX	VBITX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.23%	0.72%	+0.51%
Volatility (6M) Calculated over the trailing 6-month period	2.90%	1.67%	+1.23%
Volatility (1Y) Calculated over the trailing 1-year period	3.94%	2.29%	+1.65%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.80%	2.97%	+3.83%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.14%	2.41%	+2.73%

FMSFX vs. VBITX - Expense Ratio Comparison

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

Dividends

FMSFX vs. VBITX - Dividend Comparison

FMSFX's dividend yield for the trailing twelve months is around 3.92%, less than VBITX's 4.03% 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%
VBITX Vanguard Short-Term Bond Index Fund Institutional Shares	4.03%	3.85%	3.39%	1.99%	1.48%	1.24%	1.80%	2.26%	2.03%	1.69%	1.52%	1.44%

Frequently Asked Questions

Can I hold both FMSFX and VBITX in my portfolio?

FMSFX and VBITX have a correlation of 0.86, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FMSFX or VBITX?

FMSFX has higher volatility (1.23%) compared to VBITX (0.72%). In terms of maximum drawdown, FMSFX dropped -18.81% vs VBITX's -8.65%.

Which has better risk-adjusted returns?

FMSFX currently has the higher Sharpe Ratio (1.54 vs 1.38), 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.