MUBFX vs. ACIIX

Last updated Aug 1, 2026

MUBFX (MainStay WMC Value Fund) and ACIIX (American Century Equity Income Fund Class I) are both mutual funds - MUBFX is a Large Cap Value Equities fund managed by New York Life, while ACIIX is a Dividend fund managed by American Century. Over the past 10 years, MUBFX returned 13.11%/yr vs 9.16%/yr for ACIIX. Their correlation of 0.89 means they have usually moved in the same direction. MUBFX charges 0.70%/yr vs 0.72%/yr for ACIIX.

Performance

MUBFX vs. ACIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MainStay WMC Value Fund (MUBFX) and American Century Equity Income Fund Class I (ACIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MUBFX achieves a 12.30% return, which is significantly lower than ACIIX's 13.38% return. Over the past 10 years, MUBFX has outperformed ACIIX with an annualized return of 13.11%, while ACIIX has yielded a comparatively lower 9.16% annualized return.

MUBFX

• 1D: 0.50%
• 1M: 2.06%
• 6M: 9.18%
• YTD: 12.30%
• 1Y: 23.99%
• 3Y*: 13.51%
• 5Y*: 10.22%
• 10Y*: 13.11%
• ALL TIME*: 11.24%

ACIIX

• 1D: 0.00%
• 1M: 2.27%
• 6M: 9.01%
• YTD: 13.38%
• 1Y: 19.83%
• 3Y*: 11.90%
• 5Y*: 8.20%
• 10Y*: 9.16%
• ALL TIME*: 7.77%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
ACIIX American Century Equity Income Fund Class I	$0.00	$0.00	$0.00
MUBFX MainStay WMC Value Fund	$0.00	$0.00	$0.00

MUBFX vs. ACIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MUBFX MainStay WMC Value Fund	12.30%	14.74%	10.72%	9.62%	-4.54%	28.60%	13.62%	31.67%	-6.89%	22.71%
ACIIX American Century Equity Income Fund Class I	13.38%	12.05%	10.58%	4.25%	-2.96%	17.16%	1.19%	24.50%	-3.53%	13.69%

Correlation

The correlation between MUBFX and ACIIX is 0.85, meaning they have usually moved in the same direction, including during past declines.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.85
Correlation (3Y) Balances recent behavior with more history.	0.87
Correlation (5Y) Shows whether the relationship held over a longer period.	0.91
Correlation (10Y) Provides a long-term view across more market conditions.	0.89
Correlation (All Time) Calculated using the full available price history since Jul 8, 1998	0.89

The correlation between MUBFX and ACIIX has been stable across timeframes, ranging from 0.85 to 0.91 - a consistent structural relationship.

Return for Risk

MUBFX vs. ACIIX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

MUBFX

MUBFX Risk / Return Rank: 84
MUBFX Sharpe Ratio Rank: 82
MUBFX Sortino Ratio Rank: 81
MUBFX Omega Ratio Rank: 78
MUBFX Calmar Ratio Rank: 88
MUBFX Martin Ratio Rank: 90

ACIIX

ACIIX Risk / Return Rank: 84
ACIIX Sharpe Ratio Rank: 87
ACIIX Sortino Ratio Rank: 88
ACIIX Omega Ratio Rank: 82
ACIIX Calmar Ratio Rank: 85
ACIIX Martin Ratio Rank: 79

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

MUBFX vs. ACIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MainStay WMC Value Fund (MUBFX) and American Century Equity Income Fund Class I (ACIIX). 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.

	MUBFX	ACIIX	Difference
Sharpe ratio: Return per unit of total volatility	2.01	2.13	-0.12
Sortino ratio: Return per unit of downside risk	2.87	3.23	-0.36
Omega ratio: Gain probability vs. loss probability	1.36	1.38	-0.02
Calmar ratio: Return relative to maximum drawdown	3.23	2.87	+0.36
Martin ratio: Return relative to average drawdown	12.48	9.45	+3.03

MUBFX vs. ACIIX - Sharpe Ratio Comparison

The current MUBFX Sharpe Ratio is 2.01, which is comparable to the ACIIX Sharpe Ratio of 2.13. The chart below compares the historical Sharpe Ratios of MUBFX and ACIIX, 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

MUBFX vs. ACIIX - Drawdown Comparison

The maximum MUBFX drawdown since its inception was -53.31%, which is greater than ACIIX's maximum drawdown of -39.16%. Use the drawdown chart below to compare losses from any high point for MUBFX and ACIIX.

Drawdown Indicators

	MUBFX	ACIIX	Difference
Max Drawdown Largest peak-to-trough decline	-53.31%	-39.16%	-14.15%
Max Drawdown (1Y) Largest decline over 1 year	-6.67%	-6.38%	-0.29%
Max Drawdown (3Y) Largest decline over 3 years	-14.19%	-10.15%	-4.04%
Max Drawdown (5Y) Largest decline over 5 years	-15.61%	-13.49%	-2.12%
Max Drawdown (10Y) Largest decline over 10 years	-39.31%	-32.76%	-6.55%
Current Drawdown Current decline from peak	-0.50%	-0.63%	+0.13%
Average Drawdown Average peak-to-trough decline	-6.15%	-5.22%	-0.93%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.74%	1.93%	-0.19%

Volatility

MUBFX vs. ACIIX - Volatility Comparison

MainStay WMC Value Fund (MUBFX) and American Century Equity Income Fund Class I (ACIIX) have volatilities of 2.85% and 2.92%, 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

	MUBFX	ACIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.85%	2.92%	-0.07%
Volatility (6M) Calculated over the trailing 6-month period	7.56%	6.54%	+1.02%
Volatility (1Y) Calculated over the trailing 1-year period	10.72%	8.61%	+2.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.74%	10.78%	+3.96%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.80%	13.34%	+4.46%

MUBFX vs. ACIIX - Expense Ratio Comparison

MUBFX has a 0.70% expense ratio, which is lower than ACIIX's 0.72% expense ratio.

Dividends

MUBFX vs. ACIIX - Dividend Comparison

MUBFX's dividend yield for the trailing twelve months is around 6.57%, less than ACIIX's 9.48% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ACIIX American Century Equity Income Fund Class I	9.48%	10.55%	11.71%	8.21%	8.96%	7.02%	2.18%	7.57%	9.05%	12.14%	8.08%	10.72%
MUBFX MainStay WMC Value Fund	6.57%	7.38%	5.24%	4.49%	5.82%	81.14%	3.79%	8.43%	11.90%	11.15%	2.53%	19.99%

Frequently Asked Questions

Can I hold both MUBFX and ACIIX in my portfolio?

MUBFX and ACIIX have a correlation of 0.85, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MUBFX or ACIIX?

ACIIX has higher volatility (2.92%) compared to MUBFX (2.85%). In terms of maximum drawdown, MUBFX dropped -53.31% vs ACIIX's -39.16%.

Which has better risk-adjusted returns?

ACIIX currently has the higher Sharpe Ratio (2.13 vs 2.01), 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.