MFSI vs. MFSB

Last updated Jun 3, 2026

MFSI (MFS Active International ETF) and MFSB (MFS Active Core Plus Bond ETF) are both exchange-traded funds - MFSI is a Foreign Large Cap Equities fund actively managed by MFS, while MFSB is a Intermediate Core-Plus Bond fund actively managed by MFS. Both are actively managed. Over the past year, MFSI returned 18.65% vs 6.39% for MFSB. At a 0.34 correlation, their price movements are largely independent. MFSI charges 0.59%/yr vs 0.34%/yr for MFSB.

Performance

MFSI vs. MFSB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Active International ETF (MFSI) and MFS Active Core Plus Bond ETF (MFSB). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MFSI achieves a 7.98% return, which is significantly higher than MFSB's 0.82% return.

MFSI

• 1D: 0.83%
• 1M: 5.05%
• YTD: 7.98%
• 6M: 10.73%
• 1Y: 18.65%
• 3Y*: —
• 5Y*: —
• 10Y*: —

MFSB

• 1D: 0.08%
• 1M: 0.36%
• YTD: 0.82%
• 6M: 1.01%
• 1Y: 6.39%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

MFSI vs. MFSB - Yearly Performance Comparison

	2026 (YTD)	2025	2024
MFSI MFS Active International ETF	7.98%	26.43%	-4.21%
MFSB MFS Active Core Plus Bond ETF	0.82%	7.40%	-1.50%

Correlation

The correlation between MFSI and MFSB is 0.42, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.42
Correlation (All Time) Calculated using the full available price history since Dec 6, 2024	0.34

Return for Risk

MFSI vs. MFSB — Risk / Return Rank

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

MFSI

MFSI Risk / Return Rank: 36
MFSI Sharpe Ratio Rank: 35
MFSI Sortino Ratio Rank: 34
MFSI Omega Ratio Rank: 34
MFSI Calmar Ratio Rank: 36
MFSI Martin Ratio Rank: 41

MFSB

MFSB Risk / Return Rank: 48
MFSB Sharpe Ratio Rank: 50
MFSB Sortino Ratio Rank: 53
MFSB Omega Ratio Rank: 49
MFSB Calmar Ratio Rank: 45
MFSB Martin Ratio Rank: 43

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.

MFSI vs. MFSB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Active International ETF (MFSI) and MFS Active Core Plus Bond ETF (MFSB). 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.

	MFSI	MFSB	Difference
Sharpe ratio Return per unit of total volatility	1.29	1.77	-0.48
Sortino ratio Return per unit of downside risk	1.86	2.62	-0.76
Omega ratio Gain probability vs. loss probability	1.23	1.31	-0.08
Calmar ratio Return relative to maximum drawdown	1.79	2.26	-0.47
Martin ratio Return relative to average drawdown	6.71	7.14	-0.43
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MFSI vs. MFSB - Sharpe Ratio Comparison

The current MFSI Sharpe Ratio is 1.29, which is comparable to the MFSB Sharpe Ratio of 1.77. The chart below compares the historical Sharpe Ratios of MFSI and MFSB, 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

	MFSI	MFSB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.29	1.77	-0.48
Sharpe Ratio (All Time) Calculated using the full available price history	1.23	1.06	+0.17

Drawdowns

MFSI vs. MFSB - Drawdown Comparison

The maximum MFSI drawdown since its inception was -13.67%, which is greater than MFSB's maximum drawdown of -3.19%. Use the drawdown chart below to compare losses from any high point for MFSI and MFSB.

Drawdown Indicators

	MFSI	MFSB	Difference
Max Drawdown Largest peak-to-trough decline	-13.67%	-3.19%	-10.48%
Max Drawdown (1Y) Largest decline over 1 year	-11.17%	-2.71%	-8.46%
Current Drawdown Current decline from peak	0.00%	-1.00%	+1.00%
Average Drawdown Average peak-to-trough decline	-1.97%	-0.82%	-1.15%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.98%	0.86%	+2.12%

Volatility

MFSI vs. MFSB - Volatility Comparison

MFS Active International ETF (MFSI) has a higher volatility of 4.72% compared to MFS Active Core Plus Bond ETF (MFSB) at 1.33%. This indicates that MFSI's price experiences larger fluctuations and is considered to be riskier than MFSB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MFSI	MFSB	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.72%	1.33%	+3.39%
Volatility (6M) Calculated over the trailing 6-month period	12.11%	2.69%	+9.42%
Volatility (1Y) Calculated over the trailing 1-year period	14.60%	3.64%	+10.96%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.31%	4.23%	+12.08%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.31%	4.23%	+12.08%

MFSI vs. MFSB - Expense Ratio Comparison

MFSI has a 0.59% expense ratio, which is higher than MFSB's 0.34% expense ratio.

Dividends

MFSI vs. MFSB - Dividend Comparison

MFSI's dividend yield for the trailing twelve months is around 0.75%, less than MFSB's 4.57% yield.

Position	TTM	2025	2024
MFSB MFS Active Core Plus Bond ETF	4.57%	4.58%	0.37%
MFSI MFS Active International ETF	0.75%	0.81%	0.00%

Frequently Asked Questions

Can I hold both MFSI and MFSB in my portfolio?

MFSI and MFSB have a correlation of 0.42, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MFSI or MFSB?

MFSI has higher volatility (4.72%) compared to MFSB (1.33%). In terms of maximum drawdown, MFSI dropped -13.67% vs MFSB's -3.19%.

Which ETF is better, MFSI or MFSB?

On 1-year performance, MFSI leads with 18.65% vs 6.39% for MFSB. On fees, MFSB is cheaper at 0.34% per year. On volatility, MFSB has been the lower-risk option at 1.33%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, MFSI or MFSB?

Over the 1-year period, MFSI has performed better with a 18.65% return vs 6.39%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, MFSI or MFSB?

MFSB is cheaper with a 0.34% expense ratio, compared with 0.59% for MFSI.

Which ETF pays a higher dividend yield, MFSI or MFSB?

MFSB has the higher dividend yield at 4.57%, compared with 0.75% for MFSI.

What is the main difference between MFSI and MFSB?

MFSI is categorized as Foreign Large Cap Equities, while MFSB is Intermediate Core-Plus Bond. Their fees differ too: 0.59% for MFSI and 0.34% for MFSB.

Which has better risk-adjusted returns?

MFSB currently has the higher Sharpe Ratio (1.77 vs 1.29), 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.