VBISX vs. FIPDX

Last updated Aug 1, 2026

VBISX (Vanguard Short-Term Bond Index Fund) and FIPDX (Fidelity Inflation-Protected Bond Index Fund) are both mutual funds - VBISX is a Short-Term Bond fund managed by Vanguard, while FIPDX is a Inflation-Protected Bonds fund tracking the Bloomberg US Treasury Inflation-Protected Securities Index. Over the past 10 years, VBISX returned 1.71%/yr vs 2.41%/yr for FIPDX. Their 0.65 correlation means they have sometimes moved together and sometimes differently. VBISX charges 0.15%/yr vs 0.05%/yr for FIPDX.

Performance

VBISX vs. FIPDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Short-Term Bond Index Fund (VBISX) and Fidelity Inflation-Protected Bond Index Fund (FIPDX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VBISX achieves a 0.10% return, which is significantly lower than FIPDX's 0.55% return. Over the past 10 years, VBISX has underperformed FIPDX with an annualized return of 1.71%, while FIPDX has yielded a comparatively higher 2.41% annualized return.

VBISX

• 1D: 0.00%
• 1M: -0.29%
• 6M: -0.04%
• YTD: 0.10%
• 1Y: 2.02%
• 3Y*: 4.13%
• 5Y*: 1.35%
• 10Y*: 1.71%
• ALL TIME*: 3.36%

FIPDX

• 1D: -0.11%
• 1M: -0.44%
• 6M: 0.11%
• YTD: 0.55%
• 1Y: 2.01%
• 3Y*: 3.66%
• 5Y*: 0.31%
• 10Y*: 2.41%
• ALL TIME*: 2.16%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
FIPDX Fidelity Inflation-Protected Bond Index Fund	$0.00	$0.00	$0.00
VBISX Vanguard Short-Term Bond Index Fund	$0.00	$0.00	$0.00

VBISX vs. FIPDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VBISX Vanguard Short-Term Bond Index Fund	0.10%	5.67%	3.66%	4.54%	-5.61%	-1.35%	4.63%	4.78%	1.27%	1.10%
FIPDX Fidelity Inflation-Protected Bond Index Fund	0.55%	6.90%	2.00%	3.77%	-12.09%	5.94%	10.90%	8.32%	-1.37%	2.98%

Correlation

The correlation between VBISX and FIPDX is 0.64, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.64
Correlation (3Y) Balances recent behavior with more history.	0.72
Correlation (5Y) Shows whether the relationship held over a longer period.	0.70
Correlation (10Y) Provides a long-term view across more market conditions.	0.66
Correlation (All Time) Calculated using the full available price history since May 10, 2012	0.65

The correlation between VBISX and FIPDX has been stable across timeframes, ranging from 0.64 to 0.72 - a consistent structural relationship.

Return for Risk

VBISX vs. FIPDX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

VBISX

VBISX Risk / Return Rank: 53
VBISX Sharpe Ratio Rank: 51
VBISX Sortino Ratio Rank: 64
VBISX Omega Ratio Rank: 58
VBISX Calmar Ratio Rank: 55
VBISX Martin Ratio Rank: 37

FIPDX

FIPDX Risk / Return Rank: 23
FIPDX Sharpe Ratio Rank: 21
FIPDX Sortino Ratio Rank: 21
FIPDX Omega Ratio Rank: 20
FIPDX Calmar Ratio Rank: 30
FIPDX Martin Ratio Rank: 25

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

VBISX vs. FIPDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Short-Term Bond Index Fund (VBISX) and Fidelity Inflation-Protected Bond Index Fund (FIPDX). 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.

	VBISX	FIPDX	Difference
Sharpe ratio: Return per unit of total volatility	1.33	0.74	+0.58
Sortino ratio: Return per unit of downside risk	2.17	1.09	+1.08
Omega ratio: Gain probability vs. loss probability	1.26	1.13	+0.13
Calmar ratio: Return relative to maximum drawdown	1.92	1.27	+0.65
Martin ratio: Return relative to average drawdown	5.28	3.38	+1.90

VBISX vs. FIPDX - Sharpe Ratio Comparison

The current VBISX Sharpe Ratio is 1.33, which is higher than the FIPDX Sharpe Ratio of 0.74. The chart below compares the historical Sharpe Ratios of VBISX and FIPDX, 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

VBISX vs. FIPDX - Drawdown Comparison

The maximum VBISX drawdown since its inception was -8.79%, smaller than the maximum FIPDX drawdown of -14.32%. Use the drawdown chart below to compare losses from any high point for VBISX and FIPDX.

Drawdown Indicators

	VBISX	FIPDX	Difference
Max Drawdown Largest peak-to-trough decline	-8.79%	-14.32%	+5.53%
Max Drawdown (1Y) Largest decline over 1 year	-1.54%	-1.94%	+0.40%
Max Drawdown (3Y) Largest decline over 3 years	-1.55%	-3.95%	+2.40%
Max Drawdown (5Y) Largest decline over 5 years	-8.64%	-14.32%	+5.68%
Max Drawdown (10Y) Largest decline over 10 years	-8.79%	-14.32%	+5.53%
Current Drawdown Current decline from peak	-0.82%	-1.19%	+0.37%
Average Drawdown Average peak-to-trough decline	-0.87%	-4.43%	+3.56%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.56%	0.73%	-0.17%

Volatility

VBISX vs. FIPDX - Volatility Comparison

The current volatility for Vanguard Short-Term Bond Index Fund (VBISX) is 0.46%, while Fidelity Inflation-Protected Bond Index Fund (FIPDX) has a volatility of 0.76%. This indicates that VBISX experiences smaller price fluctuations and is considered to be less risky than FIPDX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VBISX	FIPDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.46%	0.76%	-0.30%
Volatility (6M) Calculated over the trailing 6-month period	1.69%	2.49%	-0.80%
Volatility (1Y) Calculated over the trailing 1-year period	2.24%	3.33%	-1.09%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.96%	5.96%	-3.00%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.39%	5.36%	-2.97%

VBISX vs. FIPDX - Expense Ratio Comparison

VBISX has a 0.15% expense ratio, which is higher than FIPDX's 0.05% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

VBISX vs. FIPDX - Dividend Comparison

VBISX's dividend yield for the trailing twelve months is around 3.60%, less than FIPDX's 4.36% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FIPDX Fidelity Inflation-Protected Bond Index Fund	4.36%	4.18%	3.75%	3.56%	8.87%	4.76%	1.24%	1.97%	2.26%	1.29%	1.34%	0.38%
VBISX Vanguard Short-Term Bond Index Fund	3.60%	3.44%	3.29%	2.10%	1.38%	1.16%	1.72%	2.16%	1.92%	1.58%	1.42%	1.34%

Frequently Asked Questions

Can I hold both VBISX and FIPDX in my portfolio?

VBISX and FIPDX have a correlation of 0.64, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VBISX or FIPDX?

FIPDX has higher volatility (0.76%) compared to VBISX (0.46%). In terms of maximum drawdown, VBISX dropped -8.79% vs FIPDX's -14.32%.

Which has better risk-adjusted returns?

VBISX currently has the higher Sharpe Ratio (1.33 vs 0.74), 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.