FNDSX vs. FBIIX

Last updated Jun 4, 2026

FNDSX (Fidelity Sustainability Bond Index Fund) and FBIIX (Fidelity International Bond Index Fund) are both mutual funds - FNDSX is a Total Bond Market fund managed by Fidelity, while FBIIX is a Global Bonds fund managed by Fidelity. Over the past 5 years, FNDSX returned 0.02%/yr vs 0.80%/yr for FBIIX. A 0.68 correlation means they provide meaningful diversification when combined. FNDSX charges 0.10%/yr vs 0.06%/yr for FBIIX.

Performance

FNDSX vs. FBIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Sustainability Bond Index Fund (FNDSX) and Fidelity International Bond Index Fund (FBIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FNDSX achieves a 0.42% return, which is significantly lower than FBIIX's 0.83% return.

FNDSX

• 1D: 0.00%
• 1M: 0.44%
• YTD: 0.42%
• 6M: 0.31%
• 1Y: 5.25%
• 3Y*: 3.92%
• 5Y*: 0.02%
• 10Y*: —

FBIIX

• 1D: 0.11%
• 1M: 0.99%
• YTD: 0.83%
• 6M: 0.60%
• 1Y: 2.22%
• 3Y*: 4.12%
• 5Y*: 0.80%
• 10Y*: —

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

FNDSX vs. FBIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
FNDSX Fidelity Sustainability Bond Index Fund	0.42%	7.03%	1.23%	5.44%	-13.34%	-2.22%	6.95%	0.05%
FBIIX Fidelity International Bond Index Fund	0.83%	2.66%	4.64%	7.48%	-10.84%	-1.84%	4.43%	-1.13%

Correlation

The correlation between FNDSX and FBIIX is 0.55, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.55
Correlation (3Y) Calculated over the trailing 3-year period	0.66
Correlation (5Y) Calculated over the trailing 5-year period	0.70
Correlation (All Time) Calculated using the full available price history since Oct 11, 2019	0.68

The correlation between FNDSX and FBIIX shifts across timeframes, from 0.55 (1 year) to 0.70 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

FNDSX vs. FBIIX — Risk / Return Rank

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

FNDSX

FNDSX Risk / Return Rank: 22
FNDSX Sharpe Ratio Rank: 22
FNDSX Sortino Ratio Rank: 23
FNDSX Omega Ratio Rank: 21
FNDSX Calmar Ratio Rank: 23
FNDSX Martin Ratio Rank: 21

FBIIX

FBIIX Risk / Return Rank: 8
FBIIX Sharpe Ratio Rank: 9
FBIIX Sortino Ratio Rank: 9
FBIIX Omega Ratio Rank: 9
FBIIX Calmar Ratio Rank: 8
FBIIX Martin Ratio Rank: 8

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.

FNDSX vs. FBIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Sustainability Bond Index Fund (FNDSX) and Fidelity International Bond Index Fund (FBIIX). 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.

	FNDSX	FBIIX	Difference
Sharpe ratio: Return per unit of total volatility	1.33	0.74	+0.59
Sortino ratio: Return per unit of downside risk	2.00	1.08	+0.92
Omega ratio: Gain probability vs. loss probability	1.24	1.14	+0.10
Calmar ratio: Return relative to maximum drawdown	1.79	0.80	+0.99
Martin ratio: Return relative to average drawdown	5.39	2.24	+3.15
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FNDSX vs. FBIIX - Sharpe Ratio Comparison

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

	FNDSX	FBIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.33	0.74	+0.59
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.00	0.22	-0.22
Sharpe Ratio (All Time) Calculated using the full available price history	0.33	0.23	+0.10

Drawdowns

FNDSX vs. FBIIX - Drawdown Comparison

The maximum FNDSX drawdown since its inception was -19.72%, which is greater than FBIIX's maximum drawdown of -13.79%. Use the drawdown chart below to compare losses from any high point for FNDSX and FBIIX.

Drawdown Indicators

	FNDSX	FBIIX	Difference
Max Drawdown Largest peak-to-trough decline	-19.72%	-13.79%	-5.93%
Max Drawdown (1Y) Largest decline over 1 year	-2.94%	-2.78%	-0.16%
Max Drawdown (3Y) Largest decline over 3 years	-6.11%	-2.78%	-3.33%
Max Drawdown (5Y) Largest decline over 5 years	-18.30%	-13.74%	-4.56%
Current Drawdown Current decline from peak	-3.74%	-1.11%	-2.63%
Average Drawdown Average peak-to-trough decline	-6.50%	-4.12%	-2.38%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.98%	0.99%	-0.01%

Volatility

FNDSX vs. FBIIX - Volatility Comparison

Fidelity Sustainability Bond Index Fund (FNDSX) and Fidelity International Bond Index Fund (FBIIX) have volatilities of 1.31% and 1.33%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FNDSX	FBIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.31%	1.33%	-0.02%
Volatility (6M) Calculated over the trailing 6-month period	2.81%	2.65%	+0.16%
Volatility (1Y) Calculated over the trailing 1-year period	3.98%	2.99%	+0.99%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.01%	3.59%	+2.42%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.31%	3.42%	+1.89%

FNDSX vs. FBIIX - Expense Ratio Comparison

FNDSX has a 0.10% expense ratio, which is higher than FBIIX's 0.06% 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

FNDSX vs. FBIIX - Dividend Comparison

FNDSX's dividend yield for the trailing twelve months is around 3.95%, less than FBIIX's 4.18% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018
FBIIX Fidelity International Bond Index Fund	4.18%	4.09%	3.44%	2.85%	1.02%	0.62%	0.74%	0.17%	0.00%
FNDSX Fidelity Sustainability Bond Index Fund	3.95%	3.84%	3.53%	2.84%	1.55%	1.17%	1.79%	3.17%	1.56%

Frequently Asked Questions

Can I hold both FNDSX and FBIIX in my portfolio?

FNDSX and FBIIX have a correlation of 0.55, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FNDSX or FBIIX?

FBIIX has higher volatility (1.33%) compared to FNDSX (1.31%). In terms of maximum drawdown, FNDSX dropped -19.72% vs FBIIX's -13.79%.

Which has better risk-adjusted returns?

FNDSX 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.