MFBFX vs. ACISX

Last updated Jun 3, 2026

MFBFX (MFS Corporate Bond Fund) and ACISX (AB Corporate Income Shares) are both Corporate Bonds funds. Over the past 10 years, MFBFX returned 2.40%/yr vs 3.04%/yr for ACISX. With a 0.95 correlation, they move nearly in lockstep. MFBFX charges 0.76%/yr vs 0.00%/yr for ACISX.

Performance

MFBFX vs. ACISX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Corporate Bond Fund (MFBFX) and AB Corporate Income Shares (ACISX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MFBFX achieves a 0.61% return, which is significantly lower than ACISX's 0.98% return. Over the past 10 years, MFBFX has underperformed ACISX with an annualized return of 2.40%, while ACISX has yielded a comparatively higher 3.04% annualized return.

MFBFX

• 1D: -0.08%
• 1M: 0.45%
• YTD: 0.61%
• 6M: 0.68%
• 1Y: 6.15%
• 3Y*: 4.90%
• 5Y*: 0.02%
• 10Y*: 2.40%

ACISX

• 1D: 0.00%
• 1M: 0.54%
• YTD: 0.98%
• 6M: 1.01%
• 1Y: 7.00%
• 3Y*: 5.97%
• 5Y*: 0.72%
• 10Y*: 3.04%

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

MFBFX vs. ACISX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MFBFX MFS Corporate Bond Fund	0.61%	7.35%	2.03%	8.09%	-17.27%	-1.47%	11.01%	14.43%	-3.19%	6.08%
ACISX AB Corporate Income Shares	0.98%	8.44%	3.04%	7.65%	-16.27%	-1.23%	11.27%	16.95%	-2.81%	6.19%

Correlation

The correlation between MFBFX and ACISX 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	0.97
Correlation (5Y) Calculated over the trailing 5-year period	0.97
Correlation (10Y) Calculated over the trailing 10-year period	0.97
Correlation (All Time) Calculated using the full available price history since Aug 8, 2012	0.95

The correlation between MFBFX and ACISX has been stable across timeframes, ranging from 0.95 to 0.97 - a consistent structural relationship.

Return for Risk

MFBFX vs. ACISX — Risk / Return Rank

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

MFBFX

MFBFX Risk / Return Rank: 25
MFBFX Sharpe Ratio Rank: 23
MFBFX Sortino Ratio Rank: 24
MFBFX Omega Ratio Rank: 23
MFBFX Calmar Ratio Rank: 28
MFBFX Martin Ratio Rank: 28

ACISX

ACISX Risk / Return Rank: 32
ACISX Sharpe Ratio Rank: 30
ACISX Sortino Ratio Rank: 32
ACISX Omega Ratio Rank: 30
ACISX Calmar Ratio Rank: 35
ACISX Martin Ratio Rank: 33

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.

MFBFX vs. ACISX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Corporate Bond Fund (MFBFX) and AB Corporate Income Shares (ACISX). 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.

	MFBFX	ACISX	Difference
Sharpe ratio Return per unit of total volatility	1.41	1.59	-0.18
Sortino ratio Return per unit of downside risk	2.09	2.37	-0.28
Omega ratio Gain probability vs. loss probability	1.25	1.29	-0.04
Calmar ratio Return relative to maximum drawdown	2.01	2.26	-0.25
Martin ratio Return relative to average drawdown	6.78	7.57	-0.79
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MFBFX vs. ACISX - Sharpe Ratio Comparison

The current MFBFX Sharpe Ratio is 1.41, which is comparable to the ACISX Sharpe Ratio of 1.59. The chart below compares the historical Sharpe Ratios of MFBFX and ACISX, 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

	MFBFX	ACISX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.41	1.59	-0.18
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.00	0.11	-0.11
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.42	0.51	-0.09
Sharpe Ratio (All Time) Calculated using the full available price history	0.48	0.58	-0.10

Drawdowns

MFBFX vs. ACISX - Drawdown Comparison

The maximum MFBFX drawdown since its inception was -29.78%, which is greater than ACISX's maximum drawdown of -22.65%. Use the drawdown chart below to compare losses from any high point for MFBFX and ACISX.

Drawdown Indicators

	MFBFX	ACISX	Difference
Max Drawdown Largest peak-to-trough decline	-29.78%	-22.65%	-7.13%
Max Drawdown (1Y) Largest decline over 1 year	-3.17%	-3.26%	+0.09%
Max Drawdown (3Y) Largest decline over 3 years	-6.83%	-6.56%	-0.27%
Max Drawdown (5Y) Largest decline over 5 years	-23.44%	-22.65%	-0.79%
Max Drawdown (10Y) Largest decline over 10 years	-23.44%	-22.65%	-0.79%
Current Drawdown Current decline from peak	-2.95%	-0.81%	-2.14%
Average Drawdown Average peak-to-trough decline	-6.19%	-4.46%	-1.73%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.94%	0.98%	-0.04%

Volatility

MFBFX vs. ACISX - Volatility Comparison

MFS Corporate Bond Fund (MFBFX) and AB Corporate Income Shares (ACISX) have volatilities of 1.43% and 1.50%, 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

	MFBFX	ACISX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.43%	1.50%	-0.07%
Volatility (6M) Calculated over the trailing 6-month period	3.05%	3.17%	-0.12%
Volatility (1Y) Calculated over the trailing 1-year period	4.15%	4.30%	-0.15%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.40%	6.49%	-0.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.73%	6.01%	-0.28%

MFBFX vs. ACISX - Expense Ratio Comparison

MFBFX has a 0.76% expense ratio, which is higher than ACISX's 0.00% expense ratio.

Dividends

MFBFX vs. ACISX - Dividend Comparison

MFBFX's dividend yield for the trailing twelve months is around 4.53%, less than ACISX's 5.06% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ACISX AB Corporate Income Shares	5.06%	5.10%	4.97%	3.66%	3.48%	3.44%	5.62%	4.77%	3.99%	3.28%	3.54%	3.63%
MFBFX MFS Corporate Bond Fund	4.53%	4.54%	3.74%	3.16%	2.46%	5.61%	3.47%	3.01%	3.15%	3.07%	3.27%	4.16%

Frequently Asked Questions

Can I hold both MFBFX and ACISX in my portfolio?

With a correlation of 0.96, MFBFX and ACISX 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, MFBFX or ACISX?

ACISX has higher volatility (1.50%) compared to MFBFX (1.43%). In terms of maximum drawdown, MFBFX dropped -29.78% vs ACISX's -22.65%.

Which has better risk-adjusted returns?

ACISX currently has the higher Sharpe Ratio (1.59 vs 1.41), 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.