MFSB — MFS Active Core Plus Bond ETF
Data updated: 2026-07-27
MFSB — MFS Active Core Plus Bond ETF. Intermediate Total / Aggregate Bond · $423.77M AUM · 0.34% expense ratio. Holdings, fees, performance and SEC filings.
MFSB Fund Overview
MFSB — MFS Active Core Plus Bond ETF is a US ETF managed by MFS Active Exchange Traded Funds Trust, categorised as Intermediate Total / Aggregate Bond. ABC INVEST provides holdings, performance, costs, cashflows, risk data, prospectus documents and SEC filings, sourced from SEC filings.
- Type: US ETF
- Manager: MFS Active Exchange Traded Funds Trust
- Category: Intermediate Total / Aggregate Bond
- Assets under management: $423.77M
- 1-year return: 6.0%
- Ticker: MFSB
- SEC CIK: 0002018846
- SEC series ID: S000085666
- Share class ID: C000251000
MFSB Holdings
Top 10 holdings of MFS Active Core Plus Bond ETF by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| United States Treasury | 7.75% |
| United States Treasury | 3.84% |
| United States Treasury | 3.49% |
| United States Treasury | 3.22% |
| State Street Global Advisors | 2.82% |
| United States Treasury | 1.23% |
| United States Treasury | 1.19% |
| United States Treasury | 1.18% |
| Umbs, Tba | 0.78% |
| United States Treasury | 0.72% |
MFSB Portfolio Allocation
Asset-class allocation of MFS Active Core Plus Bond ETF by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Fixed Income | 65.8% |
| Securitized | 33.3% |
| Cash & Equivalents | 2.8% |
MFSB Performance
Total returns for MFSB (as of 2026-09-01), from SEC filings.
| Period | Total return |
|---|---|
| YTD | 0.8% |
| 1 year | 6.0% |
MFSB Risk Information
Risk metrics for MFSB, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 3.3%
MFSB Costs and Fees
MFSB costs about $34 per $10,000 invested per year in fund expenses.
- Net expense ratio: 0.34%
- Gross expense ratio: 0.34%
- Portfolio turnover: 49%
- Brokerage commissions: 0.35 bps of average net assets (SEC N-CEN)
MFSB Cashflows
Over the 12 months to 2026-05, MFS Active Core Plus Bond ETF had net inflows of $384.24M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-05 | $15.51M |
| 2026-04 | $36.34M |
| 2026-03 | $145.27M |
| 2026-02 | $37.42M |
| 2026-01 | $33.42M |
| 2025-12 | $10.08M |
MFSB Debt Constituents
Largest debt holdings of MFS Active Core Plus Bond ETF by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| United States Treasury | 7.75% |
| United States Treasury | 3.84% |
| United States Treasury | 3.49% |
| United States Treasury | 3.22% |
| United States Treasury | 1.23% |
| United States Treasury | 1.19% |
| United States Treasury | 1.18% |
| United States Treasury | 0.72% |
| Boston Properties LP | 0.61% |
| Highwoods Realty LP | 0.59% |
MFSB Prospectus and SEC Filings
Official MFS Active Core Plus Bond ETF filings on SEC EDGAR — prospectus, portfolio holdings and annual reports.
- Prospectus (485BPOS) — filed 2026-06-25
- Prospectus (485BPOS) — filed 2025-06-26
- Prospectus supplement (497) — filed 2024-12-05
- Portfolio holdings (N-PORT) — filed 2026-07-27
- Portfolio holdings (N-PORT) — filed 2026-04-24
- Portfolio holdings (N-PORT) — filed 2026-01-26
- Annual census (N-CEN) — filed 2026-05-14
- Annual census (N-CEN) — filed 2025-05-14
Related Funds
Other Intermediate Total / Aggregate Bond funds tracked on ABC INVEST:
Data Sources
ABC INVEST compiles this page from public filings made to the U.S. Securities and Exchange Commission (SEC) through EDGAR: portfolio holdings and monthly cashflows from Form N-PORT, expenses and returns from fund prospectuses (Form 485BPOS) and the SEC DERA Risk/Return Summary data sets, annual data from Form N-CEN, and shareholder reports from Form N-CSR.