FXAIX vs. FUMBX

Last updated Jun 13, 2026

FXAIX (Fidelity 500 Index Fund) and FUMBX (Fidelity Short-Term Treasury Bond Index Fund) are both mutual funds - FXAIX is a S&P 500 fund tracking the S&P 500 Index, while FUMBX is a Government Bonds fund tracking the Bloomberg Barclays 1-5 Year U.S. Treasury Index. Both are passively managed. Over the past 5 years, FXAIX returned 13.34%/yr vs 1.29%/yr for FUMBX. At a correlation of -0.05, they often move in opposite directions. FXAIX charges 0.02%/yr vs 0.03%/yr for FUMBX.

Performance

FXAIX vs. FUMBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity 500 Index Fund (FXAIX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FXAIX achieves a 8.59% return, which is significantly higher than FUMBX's 0.19% return.

FXAIX

• 1D: 1.76%
• 1M: -0.55%
• YTD: 8.59%
• 6M: 8.94%
• 1Y: 23.79%
• 3Y*: 21.06%
• 5Y*: 13.34%
• 10Y*: 15.44%

FUMBX

• 1D: 0.20%
• 1M: 0.07%
• YTD: 0.19%
• 6M: 0.56%
• 1Y: 3.19%
• 3Y*: 4.03%
• 5Y*: 1.29%
• 10Y*: —

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

FXAIX vs. FUMBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FXAIX Fidelity 500 Index Fund	8.59%	17.84%	25.01%	26.29%	-18.14%	28.71%	18.42%	31.48%	-4.43%	4.82%
FUMBX Fidelity Short-Term Treasury Bond Index Fund	0.19%	5.83%	3.25%	4.47%	-5.84%	-1.38%	4.22%	4.19%	1.47%	-0.33%

Correlation

The correlation between FXAIX and FUMBX is 0.21, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.21
Correlation (3Y) Calculated over the trailing 3-year period	0.10
Correlation (5Y) Calculated over the trailing 5-year period	0.08
Correlation (All Time) Calculated using the full available price history since Oct 19, 2017	-0.05

The correlation between FXAIX and FUMBX shifts across timeframes, from -0.05 (all time) to 0.21 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

FXAIX vs. FUMBX — Risk / Return Rank

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

FXAIX

FXAIX Risk / Return Rank: 73
FXAIX Sharpe Ratio Rank: 72
FXAIX Sortino Ratio Rank: 68
FXAIX Omega Ratio Rank: 69
FXAIX Calmar Ratio Rank: 73
FXAIX Martin Ratio Rank: 84

FUMBX

FUMBX Risk / Return Rank: 54
FUMBX Sharpe Ratio Rank: 51
FUMBX Sortino Ratio Rank: 66
FUMBX Omega Ratio Rank: 62
FUMBX Calmar Ratio Rank: 50
FUMBX Martin Ratio Rank: 38

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.

FXAIX vs. FUMBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity 500 Index Fund (FXAIX) and Fidelity Short-Term Treasury Bond Index Fund (FUMBX). 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.

	FXAIX	FUMBX	Difference
Sharpe ratio: Return per unit of total volatility	1.97	1.65	+0.32
Sortino ratio: Return per unit of downside risk	2.67	2.66	+0.02
Omega ratio: Gain probability vs. loss probability	1.36	1.34	+0.02
Calmar ratio: Return relative to maximum drawdown	2.74	2.22	+0.53
Martin ratio: Return relative to average drawdown	12.46	6.76	+5.70

FXAIX vs. FUMBX - Sharpe Ratio Comparison

The current FXAIX Sharpe Ratio is 1.97, which is comparable to the FUMBX Sharpe Ratio of 1.65. The chart below compares the historical Sharpe Ratios of FXAIX and FUMBX, 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

FXAIX vs. FUMBX - Drawdown Comparison

The maximum FXAIX drawdown since its inception was -33.79%, which is greater than FUMBX's maximum drawdown of -8.83%. Use the drawdown chart below to compare losses from any high point for FXAIX and FUMBX.

Drawdown Indicators

	FXAIX	FUMBX	Difference
Max Drawdown Largest peak-to-trough decline	-33.79%	-8.83%	-24.96%
Max Drawdown (1Y) Largest decline over 1 year	-8.89%	-1.54%	-7.35%
Max Drawdown (3Y) Largest decline over 3 years	-18.76%	-1.57%	-17.19%
Max Drawdown (5Y) Largest decline over 5 years	-24.50%	-8.60%	-15.90%
Max Drawdown (10Y) Largest decline over 10 years	-33.79%	—	—
Current Drawdown Current decline from peak	-2.79%	-0.77%	-2.02%
Average Drawdown Average peak-to-trough decline	-3.79%	-1.86%	-1.93%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.95%	0.50%	+1.45%

Volatility

FXAIX vs. FUMBX - Volatility Comparison

Fidelity 500 Index Fund (FXAIX) has a higher volatility of 4.44% compared to Fidelity Short-Term Treasury Bond Index Fund (FUMBX) at 0.71%. This indicates that FXAIX's price experiences larger fluctuations and is considered to be riskier than FUMBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FXAIX	FUMBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.44%	0.71%	+3.73%
Volatility (6M) Calculated over the trailing 6-month period	9.70%	1.51%	+8.19%
Volatility (1Y) Calculated over the trailing 1-year period	12.37%	2.06%	+10.31%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.99%	2.92%	+14.07%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.10%	2.49%	+15.61%

FXAIX vs. FUMBX - Expense Ratio Comparison

FXAIX has a 0.02% expense ratio, which is lower than FUMBX's 0.03% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

FXAIX vs. FUMBX - Dividend Comparison

FXAIX's dividend yield for the trailing twelve months is around 1.06%, less than FUMBX's 3.76% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FUMBX Fidelity Short-Term Treasury Bond Index Fund	3.76%	3.51%	2.91%	1.64%	0.86%	1.15%	1.41%	1.88%	1.64%	0.34%	0.00%	0.00%
FXAIX Fidelity 500 Index Fund	1.06%	1.11%	1.25%	1.45%	1.69%	1.22%	1.60%	2.06%	2.72%	1.97%	2.52%	2.83%

Frequently Asked Questions

Can I hold both FXAIX and FUMBX in my portfolio?

FXAIX and FUMBX have a correlation of 0.21, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FXAIX or FUMBX?

FXAIX has higher volatility (4.44%) compared to FUMBX (0.71%). In terms of maximum drawdown, FXAIX dropped -33.79% vs FUMBX's -8.83%.

Which has better risk-adjusted returns?

FXAIX currently has the higher Sharpe Ratio (1.97 vs 1.65), 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.