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BFMSX vs. SPAXX
Performance
Return for Risk
Drawdowns
Volatility
Dividends

BFMSX vs. SPAXX

Last updated Jul 14, 2026
Documentation

BFMSX (BlackRock Low Duration Bond Portfolio) and SPAXX (Fidelity Government Money Market Fund) are both mutual funds - BFMSX is a Short-Term Bond fund managed by BlackRock, while SPAXX is a Money Market fund actively managed by Fidelity. Over the past 5 years, BFMSX returned 2.12%/yr vs 1.50%/yr for SPAXX. At a 0.23 correlation, their price movements are largely independent. BFMSX charges 0.41%/yr vs 0.42%/yr for SPAXX.

Performance

BFMSX vs. SPAXX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in BlackRock Low Duration Bond Portfolio (BFMSX) and Fidelity Government Money Market Fund (SPAXX). The values are adjusted to include any dividend payments, if applicable.

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Returns By Period

In the year-to-date period, BFMSX achieves a 0.97% return, which is significantly lower than SPAXX's 1.64% return.

BFMSX

1D
-0.11%
1M
0.16%
6M
0.97%
YTD
0.97%
1Y
4.06%
3Y*
5.26%
5Y*
2.12%
10Y*
2.27%

SPAXX

1D
0.00%
1M
0.27%
6M
1.64%
YTD
1.64%
1Y
3.60%
3Y*
2.52%
5Y*
1.50%
10Y*
—
*Multi-year figures are annualized to reflect compound growth (CAGR)

BFMSX vs. SPAXX - Yearly Performance Comparison

2026 (YTD)20252024202320222021
BFMSX
BlackRock Low Duration Bond Portfolio		0.97%6.20%4.94%4.96%-5.34%-0.76%
SPAXX
Fidelity Government Money Market Fund		1.64%3.96%1.54%0.41%0.00%0.00%

Correlation

The correlation between BFMSX and SPAXX is 0.39, which is low. Their price movements are largely independent, making them effective diversification partners.

Correlation
Correlation (1Y)
Calculated over the trailing 1-year period

0.39

Correlation (3Y)
Calculated over the trailing 3-year period

0.31

Correlation (5Y)
Calculated over the trailing 5-year period

0.24

Correlation (All Time)
Calculated using the full available price history since May 25, 2021

0.23

The correlation between BFMSX and SPAXX shifts across timeframes, from 0.23 (all time) to 0.39 (1 year), reflecting how their relationship changes across market environments.

Compare stocks, funds, or ETFs

Search for stocks, ETFs, and funds for a quick comparison or use the comparison tool for more options.

BlackRock Low Duration Bond Portfolio

Fidelity Government Money Market Fund

Often compared with BFMSX:
BFMSX vs. TNSHXBFMSX vs. ANBAXBFMSX vs. VIITXBFMSX vs. GPICXBFMSX vs. DBLSXBFMSX vs. DHEAXBFMSX vs. GPARX
Often compared with SPAXX:
SPAXX vs. SGOVSPAXX vs. VMFXXSPAXX vs. SNSXXSPAXX vs. SWVXXSPAXX vs. BILSPAXX vs. BNDSPAXX vs. TFLO

Return for Risk

BFMSX vs. SPAXX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.
BFMSX
BFMSX Risk / Return Rank: 8181
Overall Rank
BFMSX Sharpe Ratio Rank: 7373
Sharpe Ratio Rank
BFMSX Sortino Ratio Rank: 8787
Sortino Ratio Rank
BFMSX Omega Ratio Rank: 8787
Omega Ratio Rank
BFMSX Calmar Ratio Rank: 7474
Calmar Ratio Rank
BFMSX Martin Ratio Rank: 8686
Martin Ratio Rank
SPAXX

Risk / return metrics aren't available yet — we need at least 12 months of trading data to calculate them.

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.

BFMSX vs. SPAXX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for BlackRock Low Duration Bond Portfolio (BFMSX) and Fidelity Government Money Market Fund (SPAXX). 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.

BFMSXSPAXXDifference
Sharpe ratioReturn per unit of total volatility
1.92
3.65

-1.73

Sortino ratioReturn per unit of downside risk
3.41

—

—

Omega ratioGain probability vs. loss probability

1.49

—

—

Calmar ratioReturn relative to maximum drawdown

2.68

—

—

Martin ratioReturn relative to average drawdown

12.37

—

—

BFMSX vs. SPAXX - Sharpe Ratio Comparison

The current BFMSX Sharpe Ratio is 1.92, which is lower than the SPAXX Sharpe Ratio of 3.65. The chart below compares the historical Sharpe Ratios of BFMSX and SPAXX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

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Drawdowns

BFMSX vs. SPAXX - Drawdown Comparison

The maximum BFMSX drawdown since its inception was -12.70%, which is greater than SPAXX's maximum drawdown of 0.00%. Use the drawdown chart below to compare losses from any high point for BFMSX and SPAXX.

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Drawdown Indicators

BFMSXSPAXXDifference

Max Drawdown

Largest peak-to-trough decline

-12.70%

0.00%

-12.70%

Max Drawdown (1Y)

Largest decline over 1 year

-1.52%

0.00%

-1.52%

Max Drawdown (3Y)

Largest decline over 3 years

-1.52%

0.00%

-1.52%

Max Drawdown (5Y)

Largest decline over 5 years

-7.96%

0.00%

-7.96%

Max Drawdown (10Y)

Largest decline over 10 years

-7.96%

—

—

Current Drawdown

Current decline from peak

-0.22%

0.00%

-0.22%

Average Drawdown

Average peak-to-trough decline

-0.82%

0.00%

-0.82%

Ulcer Index

Depth and duration of drawdowns from previous peaks

0.33%

0.00%

+0.33%

Volatility

BFMSX vs. SPAXX - Volatility Comparison

BlackRock Low Duration Bond Portfolio (BFMSX) has a higher volatility of 0.67% compared to Fidelity Government Money Market Fund (SPAXX) at 0.27%. This indicates that BFMSX's price experiences larger fluctuations and is considered to be riskier than SPAXX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

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Volatility by Period

BFMSXSPAXXDifference

Volatility (1M)

Calculated over the trailing 1-month period

0.67%

0.27%

+0.40%

Volatility (6M)

Calculated over the trailing 6-month period

1.73%

0.65%

+1.08%

Volatility (1Y)

Calculated over the trailing 1-year period

2.13%

1.02%

+1.11%

Volatility (5Y)

Calculated over the trailing 5-year period, annualized

2.36%

0.70%

+1.66%

Volatility (10Y)

Calculated over the trailing 10-year period, annualized

2.12%

0.69%

+1.43%

BFMSX vs. SPAXX - Expense Ratio Comparison

BFMSX has a 0.41% expense ratio, which is lower than SPAXX's 0.42% expense ratio.

Dividends

BFMSX vs. SPAXX - Dividend Comparison

BFMSX's dividend yield for the trailing twelve months is around 4.67%, more than SPAXX's 3.53% yield.

PositionTTM20252024202320222021202020192018201720162015
BFMSX
BlackRock Low Duration Bond Portfolio		4.67%4.56%4.14%3.34%2.67%1.23%2.04%2.63%2.51%2.17%1.76%1.87%
SPAXX
Fidelity Government Money Market Fund		3.53%3.88%1.53%0.41%0.00%0.00%0.00%0.00%0.00%0.00%0.00%0.00%

Frequently Asked Questions

BFMSX and SPAXX have a correlation of 0.39, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

BFMSX has higher volatility (0.67%) compared to SPAXX (0.27%). In terms of maximum drawdown, BFMSX dropped -12.70% vs SPAXX's 0.00%.

SPAXX currently has the higher Sharpe Ratio (3.65 vs 1.92), 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.

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