MMUFX vs. BULIX

Last updated Jun 25, 2026

MMUFX (MFS Utilities Fund) and BULIX (American Century Utilities Fund) are both Utilities Equities funds. Over the past 10 years, MMUFX returned 9.02%/yr vs 7.01%/yr for BULIX. Their correlation of 0.87 suggests significant overlap in exposure. MMUFX charges 0.99%/yr vs 0.65%/yr for BULIX.

Performance

MMUFX vs. BULIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Utilities Fund (MMUFX) and American Century Utilities Fund (BULIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with MMUFX having a 7.77% return and BULIX slightly higher at 7.92%. Over the past 10 years, MMUFX has outperformed BULIX with an annualized return of 9.02%, while BULIX has yielded a comparatively lower 7.01% annualized return.

MMUFX

• 1D: 0.60%
• 1M: -0.41%
• YTD: 7.77%
• 6M: 7.60%
• 1Y: 15.59%
• 3Y*: 11.05%
• 5Y*: 8.26%
• 10Y*: 9.02%

BULIX

• 1D: 0.87%
• 1M: 0.22%
• YTD: 7.92%
• 6M: 7.69%
• 1Y: 14.60%
• 3Y*: 16.23%
• 5Y*: 9.36%
• 10Y*: 7.01%

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

MMUFX vs. BULIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MMUFX MFS Utilities Fund	7.77%	14.32%	11.38%	-2.28%	0.35%	13.86%	6.04%	24.91%	0.85%	14.69%
BULIX American Century Utilities Fund	7.92%	16.76%	24.32%	-7.51%	-4.37%	13.77%	-2.38%	19.94%	1.82%	0.59%

Correlation

The correlation between MMUFX and BULIX is 0.96 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.96
Correlation (3Y) Calculated over the trailing 3-year period	0.96
Correlation (5Y) Calculated over the trailing 5-year period	0.96
Correlation (10Y) Calculated over the trailing 10-year period	0.91
Correlation (All Time) Calculated using the full available price history since Feb 26, 1993	0.87

The correlation between MMUFX and BULIX has been stable across timeframes, ranging from 0.87 to 0.96 - a consistent structural relationship.

Return for Risk

MMUFX vs. BULIX — Risk / Return Rank

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

MMUFX

MMUFX Risk / Return Rank: 22
MMUFX Sharpe Ratio Rank: 20
MMUFX Sortino Ratio Rank: 18
MMUFX Omega Ratio Rank: 19
MMUFX Calmar Ratio Rank: 30
MMUFX Martin Ratio Rank: 21

BULIX

BULIX Risk / Return Rank: 18
BULIX Sharpe Ratio Rank: 18
BULIX Sortino Ratio Rank: 16
BULIX Omega Ratio Rank: 16
BULIX Calmar Ratio Rank: 25
BULIX Martin Ratio Rank: 16

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.

MMUFX vs. BULIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Utilities Fund (MMUFX) and American Century Utilities Fund (BULIX). 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.

	MMUFX	BULIX	Difference
Sharpe ratio: Return per unit of total volatility	1.15	1.08	+0.06
Sortino ratio: Return per unit of downside risk	1.60	1.52	+0.08
Omega ratio: Gain probability vs. loss probability	1.20	1.19	+0.01
Calmar ratio: Return relative to maximum drawdown	1.87	1.69	+0.18
Martin ratio: Return relative to average drawdown	4.58	3.87	+0.71

MMUFX vs. BULIX - Sharpe Ratio Comparison

The current MMUFX Sharpe Ratio is 1.15, which is comparable to the BULIX Sharpe Ratio of 1.08. The chart below compares the historical Sharpe Ratios of MMUFX and BULIX, 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

MMUFX vs. BULIX - Drawdown Comparison

The maximum MMUFX drawdown since its inception was -56.03%, roughly equal to the maximum BULIX drawdown of -55.21%. Use the drawdown chart below to compare losses from any high point for MMUFX and BULIX.

Drawdown Indicators

	MMUFX	BULIX	Difference
Max Drawdown Largest peak-to-trough decline	-56.03%	-55.21%	-0.82%
Max Drawdown (1Y) Largest decline over 1 year	-8.75%	-8.93%	+0.18%
Max Drawdown (3Y) Largest decline over 3 years	-17.72%	-16.54%	-1.18%
Max Drawdown (5Y) Largest decline over 5 years	-21.64%	-24.56%	+2.92%
Max Drawdown (10Y) Largest decline over 10 years	-35.82%	-33.86%	-1.96%
Current Drawdown Current decline from peak	-4.52%	-4.26%	-0.26%
Average Drawdown Average peak-to-trough decline	-8.75%	-10.02%	+1.27%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.57%	3.90%	-0.33%

Volatility

MMUFX vs. BULIX - Volatility Comparison

MFS Utilities Fund (MMUFX) and American Century Utilities Fund (BULIX) have volatilities of 4.91% and 5.07%, 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

	MMUFX	BULIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.91%	5.07%	-0.16%
Volatility (6M) Calculated over the trailing 6-month period	11.58%	11.15%	+0.43%
Volatility (1Y) Calculated over the trailing 1-year period	14.36%	14.00%	+0.36%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.82%	16.70%	-0.88%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.61%	18.07%	-1.46%

MMUFX vs. BULIX - Expense Ratio Comparison

MMUFX has a 0.99% expense ratio, which is higher than BULIX's 0.65% expense ratio.

Dividends

MMUFX vs. BULIX - Dividend Comparison

MMUFX's dividend yield for the trailing twelve months is around 3.55%, less than BULIX's 10.49% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BULIX American Century Utilities Fund	10.49%	11.60%	2.36%	2.65%	7.78%	7.50%	7.55%	2.97%	6.91%	7.70%	6.99%	5.87%
MMUFX MFS Utilities Fund	3.55%	3.83%	3.72%	5.82%	8.68%	5.61%	5.80%	6.85%	4.29%	2.67%	3.72%	9.09%

Frequently Asked Questions

Can I hold both MMUFX and BULIX in my portfolio?

With a correlation of 0.96, MMUFX and BULIX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, MMUFX or BULIX?

BULIX has higher volatility (5.07%) compared to MMUFX (4.91%). In terms of maximum drawdown, MMUFX dropped -56.03% vs BULIX's -55.21%.

Which has better risk-adjusted returns?

MMUFX currently has the higher Sharpe Ratio (1.15 vs 1.08), 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.