MFSB vs. BYLD

Last updated Jun 4, 2026

MFSB (MFS Active Core Plus Bond ETF) and BYLD (iShares Yield Optimized Bond ETF) are both Intermediate Core-Plus Bond funds. MFSB is actively managed, while BYLD is passively managed. Over the past year, MFSB returned 6.16% vs 7.01% for BYLD. A 0.80 correlation means they provide meaningful diversification when combined. MFSB charges 0.34%/yr vs 0.17%/yr for BYLD.

Performance

MFSB vs. BYLD - Performance Comparison

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

Returns By Period

In the year-to-date period, MFSB achieves a 0.56% return, which is significantly lower than BYLD's 1.23% return.

MFSB

• 1D: -0.26%
• 1M: 0.38%
• YTD: 0.56%
• 6M: 0.61%
• 1Y: 6.16%
• 3Y*: —
• 5Y*: —
• 10Y*: —

BYLD

• 1D: -0.18%
• 1M: 0.61%
• YTD: 1.23%
• 6M: 1.35%
• 1Y: 7.01%
• 3Y*: 6.49%
• 5Y*: 2.21%
• 10Y*: 3.01%

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

MFSB vs. BYLD - Yearly Performance Comparison

	2026 (YTD)	2025	2024
MFSB MFS Active Core Plus Bond ETF	0.56%	7.40%	-1.50%
BYLD iShares Yield Optimized Bond ETF	1.23%	8.41%	-1.38%

Correlation

The correlation between MFSB and BYLD is 0.80, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.80
Correlation (All Time) Calculated using the full available price history since Dec 6, 2024	0.80

The correlation between MFSB and BYLD has been stable across timeframes, ranging from 0.80 to 0.80 - a consistent structural relationship.

Return for Risk

MFSB vs. BYLD — Risk / Return Rank

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

MFSB

MFSB Risk / Return Rank: 49
MFSB Sharpe Ratio Rank: 50
MFSB Sortino Ratio Rank: 53
MFSB Omega Ratio Rank: 49
MFSB Calmar Ratio Rank: 47
MFSB Martin Ratio Rank: 44

BYLD

BYLD Risk / Return Rank: 55
BYLD Sharpe Ratio Rank: 53
BYLD Sortino Ratio Rank: 57
BYLD Omega Ratio Rank: 56
BYLD Calmar Ratio Rank: 52
BYLD Martin Ratio Rank: 59

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.

MFSB vs. BYLD - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Active Core Plus Bond ETF (MFSB) and iShares Yield Optimized Bond ETF (BYLD). 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.

	MFSB	BYLD	Difference
Sharpe ratio: Return per unit of total volatility	1.70	1.85	-0.15
Sortino ratio: Return per unit of downside risk	2.51	2.76	-0.24
Omega ratio: Gain probability vs. loss probability	1.30	1.35	-0.05
Calmar ratio: Return relative to maximum drawdown	2.28	2.60	-0.31
Martin ratio: Return relative to average drawdown	7.17	10.54	-3.37
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MFSB vs. BYLD - Sharpe Ratio Comparison

The current MFSB Sharpe Ratio is 1.70, which is comparable to the BYLD Sharpe Ratio of 1.85. The chart below compares the historical Sharpe Ratios of MFSB and BYLD, 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

	MFSB	BYLD	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.70	1.85	-0.15
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	—	0.43	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.56	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.01	0.57	+0.44

Drawdowns

MFSB vs. BYLD - Drawdown Comparison

The maximum MFSB drawdown since its inception was -3.19%, smaller than the maximum BYLD drawdown of -14.75%. Use the drawdown chart below to compare losses from any high point for MFSB and BYLD.

Drawdown Indicators

	MFSB	BYLD	Difference
Max Drawdown Largest peak-to-trough decline	-3.19%	-14.75%	+11.56%
Max Drawdown (1Y) Largest decline over 1 year	-2.71%	-2.71%	0.00%
Max Drawdown (3Y) Largest decline over 3 years	—	-3.94%	—
Max Drawdown (5Y) Largest decline over 5 years	—	-14.65%	—
Max Drawdown (10Y) Largest decline over 10 years	—	-14.75%	—
Current Drawdown Current decline from peak	-1.26%	-0.34%	-0.92%
Average Drawdown Average peak-to-trough decline	-0.82%	-2.51%	+1.69%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.86%	0.67%	+0.19%

Volatility

MFSB vs. BYLD - Volatility Comparison

The current volatility for MFS Active Core Plus Bond ETF (MFSB) is 1.33%, while iShares Yield Optimized Bond ETF (BYLD) has a volatility of 1.42%. This indicates that MFSB experiences smaller price fluctuations and is considered to be less risky than BYLD based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MFSB	BYLD	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.33%	1.42%	-0.09%
Volatility (6M) Calculated over the trailing 6-month period	2.68%	2.94%	-0.26%
Volatility (1Y) Calculated over the trailing 1-year period	3.64%	3.82%	-0.18%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	4.23%	5.20%	-0.97%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.23%	5.43%	-1.20%

MFSB vs. BYLD - Expense Ratio Comparison

MFSB has a 0.34% expense ratio, which is higher than BYLD's 0.17% expense ratio.

Dividends

MFSB vs. BYLD - Dividend Comparison

MFSB's dividend yield for the trailing twelve months is around 4.59%, less than BYLD's 5.36% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BYLD iShares Yield Optimized Bond ETF	5.36%	5.32%	5.31%	4.45%	3.39%	2.18%	3.41%	3.67%	4.22%	3.22%	3.14%	3.37%
MFSB MFS Active Core Plus Bond ETF	4.59%	4.58%	0.37%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both MFSB and BYLD in my portfolio?

MFSB and BYLD have a correlation of 0.80, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MFSB or BYLD?

BYLD has higher volatility (1.42%) compared to MFSB (1.33%). In terms of maximum drawdown, MFSB dropped -3.19% vs BYLD's -14.75%.

Which ETF is better, MFSB or BYLD?

On 1-year performance, BYLD leads with 7.01% vs 6.16% for MFSB. On fees, BYLD is cheaper at 0.17% per year. Their volatility is very similar. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, MFSB or BYLD?

Over the 1-year period, BYLD has performed better with a 7.01% return vs 6.16%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, MFSB or BYLD?

BYLD is cheaper with a 0.17% expense ratio, compared with 0.34% for MFSB.

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

BYLD has the higher dividend yield at 5.36%, compared with 4.59% for MFSB.

What is the main difference between MFSB and BYLD?

They also come from different issuers: MFS and iShares. Their fees differ too: 0.34% for MFSB and 0.17% for BYLD.

Which has better risk-adjusted returns?

BYLD currently has the higher Sharpe Ratio (1.85 vs 1.70), 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.