SPAXX vs. BRK-B

Last updated Jun 9, 2026

SPAXX (Fidelity Government Money Market Fund) is Money Market fund actively managed by Fidelity, while BRK-B (Berkshire Hathaway Inc.) is a stock. Over the past 5 years, SPAXX returned 1.45%/yr vs 11.03%/yr for BRK-B. At a 0.02 correlation, their price movements are largely independent.

Performance

SPAXX vs. BRK-B - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Government Money Market Fund (SPAXX) and Berkshire Hathaway Inc. (BRK-B). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SPAXX achieves a 1.37% return, which is significantly higher than BRK-B's -3.11% return.

SPAXX

• 1D: 0.00%
• 1M: 0.28%
• YTD: 1.37%
• 6M: 1.67%
• 1Y: 3.66%
• 3Y*: 2.42%
• 5Y*: 1.45%
• 10Y*: —

BRK-B

• 1D: -0.23%
• 1M: 2.32%
• YTD: -3.11%
• 6M: -2.06%
• 1Y: -1.32%
• 3Y*: 13.25%
• 5Y*: 11.03%
• 10Y*: 13.14%

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

SPAXX vs. BRK-B - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021
SPAXX Fidelity Government Money Market Fund	1.37%	3.96%	1.54%	0.41%	0.00%	0.00%
BRK-B Berkshire Hathaway Inc.	-3.11%	10.89%	27.09%	15.46%	3.31%	3.20%

Correlation

The correlation between SPAXX and BRK-B is 0.04, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.04
Correlation (3Y) Calculated over the trailing 3-year period	0.02
Correlation (5Y) Calculated over the trailing 5-year period	0.02
Correlation (All Time) Calculated using the full available price history since May 25, 2021	0.02

Return for Risk

SPAXX vs. BRK-B — Risk / Return Rank

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

BRK-B

BRK-B Risk / Return Rank: 35
BRK-B Sharpe Ratio Rank: 38
BRK-B Sortino Ratio Rank: 30
BRK-B Omega Ratio Rank: 30
BRK-B Calmar Ratio Rank: 38
BRK-B Martin Ratio Rank: 37

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.

SPAXX vs. BRK-B - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Government Money Market Fund (SPAXX) and Berkshire Hathaway Inc. (BRK-B). 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.

	SPAXX	BRK-B	Difference
Sharpe ratio: Return per unit of total volatility	3.65	-0.09	+3.74
Sortino ratio: Return per unit of downside risk	—	-0.03	—
Omega ratio: Gain probability vs. loss probability	—	1.00	—
Calmar ratio: Return relative to maximum drawdown	—	-0.14	—
Martin ratio: Return relative to average drawdown	—	-0.30	—
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SPAXX vs. BRK-B - Sharpe Ratio Comparison

The current SPAXX Sharpe Ratio is 3.65, which is higher than the BRK-B Sharpe Ratio of -0.09. The chart below compares the historical Sharpe Ratios of SPAXX and BRK-B, 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

	SPAXX	BRK-B	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	3.65	-0.09	+3.74
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	2.13	0.65	+1.48
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.68	—
Sharpe Ratio (All Time) Calculated using the full available price history	2.12	0.48	+1.64

Drawdowns

SPAXX vs. BRK-B - Drawdown Comparison

The maximum SPAXX drawdown since its inception was 0.00%, smaller than the maximum BRK-B drawdown of -53.86%. Use the drawdown chart below to compare losses from any high point for SPAXX and BRK-B.

Drawdown Indicators

	SPAXX	BRK-B	Difference
Max Drawdown Largest peak-to-trough decline	0.00%	-53.86%	+53.86%
Max Drawdown (1Y) Largest decline over 1 year	0.00%	-9.42%	+9.42%
Max Drawdown (3Y) Largest decline over 3 years	0.00%	-14.95%	+14.95%
Max Drawdown (5Y) Largest decline over 5 years	0.00%	-26.58%	+26.58%
Max Drawdown (10Y) Largest decline over 10 years	—	-29.57%	—
Current Drawdown Current decline from peak	0.00%	-9.78%	+9.78%
Average Drawdown Average peak-to-trough decline	0.00%	-11.07%	+11.07%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.00%	4.49%	-4.49%

Volatility

SPAXX vs. BRK-B - Volatility Comparison

The current volatility for Fidelity Government Money Market Fund (SPAXX) is 0.28%, while Berkshire Hathaway Inc. (BRK-B) has a volatility of 3.98%. This indicates that SPAXX experiences smaller price fluctuations and is considered to be less risky than BRK-B based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SPAXX	BRK-B	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.28%	3.98%	-3.70%
Volatility (6M) Calculated over the trailing 6-month period	0.72%	10.87%	-10.15%
Volatility (1Y) Calculated over the trailing 1-year period	1.03%	14.38%	-13.35%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.69%	17.13%	-16.44%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.69%	19.44%	-18.75%

Dividends

SPAXX vs. BRK-B - Dividend Comparison

SPAXX's dividend yield for the trailing twelve months is around 3.59%, while BRK-B has not paid dividends to shareholders.

Position	TTM	2025	2024	2023
BRK-B Berkshire Hathaway Inc.	0.00%	0.00%	0.00%	0.00%
SPAXX Fidelity Government Money Market Fund	3.59%	3.88%	1.53%	0.41%

Frequently Asked Questions

Can I hold both SPAXX and BRK-B in my portfolio?

SPAXX and BRK-B have a correlation of 0.04, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, SPAXX or BRK-B?

BRK-B has higher volatility (3.98%) compared to SPAXX (0.28%). In terms of maximum drawdown, SPAXX dropped 0.00% vs BRK-B's -53.86%.

Which has better risk-adjusted returns?

SPAXX currently has the higher Sharpe Ratio (3.65 vs -0.09), 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.