TSSIX — Thornburg Strategic Municipal Income Fund
Data updated: 2026-08-24
TSSIX — Thornburg Strategic Municipal Income Fund. Long Municipal - National Bond · $428.33M AUM. Holdings, fees, performance and SEC filings.
TSSIX Fund Overview
TSSIX — Thornburg Strategic Municipal Income Fund is a US mutual fund managed by Thornburg Investment Trust, categorised as Long Municipal - National Bond. ABC INVEST provides holdings, performance, costs, cashflows, risk data, prospectus documents and SEC filings, sourced from SEC filings.
- Type: US mutual fund
- Manager: Thornburg Investment Trust
- Category: Long Municipal - National Bond
- Assets under management: $428.33M
- 1-year return: 6.7%
- Ticker: TSSIX
- SEC CIK: 0000816153
- SEC series ID: S000025152
- Share class ID: C000075020
TSSIX Holdings
Top 10 holdings of Thornburg Strategic Municipal Income Fund by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| County of Montgomery OH | 1.71% |
| Illinois Finance Authority | 1.56% |
| Kentucky Public Energy Authority | 1.30% |
| Patriots Energy Group Financing Agency | 1.25% |
| Kentucky Public Energy Authority | 1.25% |
| California Community Choice Financing Authority | 1.04% |
| Tarrant County Housing Finance Corp | 1.00% |
| New York State Housing Finance Agency | 0.94% |
| Main Street Natural Gas Inc | 0.92% |
| Chandler Industrial Development Authority | 0.86% |
TSSIX Portfolio Allocation
Asset-class allocation of Thornburg Strategic Municipal Income Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Fixed Income | 99.3% |
| Equity | 0.1% |
TSSIX Performance
Total returns for TSSIX (as of 2026-09-01), from SEC filings.
| Period | Total return |
|---|---|
| YTD | 2.8% |
| 1 year | 6.7% |
| 3 years (annualised) | 4.6% |
| 5 years (annualised) | 1.5% |
TSSIX Risk Information
Risk metrics for TSSIX, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 3.4%
TSSIX Costs and Fees
TSSIX costs about $50 per $10,000 invested per year in fund expenses.
- Net expense ratio: 0.50%
- Gross expense ratio: 0.99%
- Portfolio turnover: 59%
- Brokerage commissions: 0.00 bps of average net assets (SEC N-CEN)
TSSIX Cashflows
Over the 12 months to 2026-06, Thornburg Strategic Municipal Income Fund had net inflows of $55.57M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-06 | $2.62M |
| 2026-05 | $10.68M |
| 2026-04 | $2.81M |
| 2026-03 | $3.71M |
| 2026-02 | $4.69M |
| 2026-01 | −$390.36K |
TSSIX Debt Constituents
Largest debt holdings of Thornburg Strategic Municipal Income Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| County of Montgomery OH | 1.71% |
| Illinois Finance Authority | 1.56% |
| Kentucky Public Energy Authority | 1.30% |
| Patriots Energy Group Financing Agency | 1.25% |
| Kentucky Public Energy Authority | 1.25% |
| California Community Choice Financing Authority | 1.04% |
| Tarrant County Housing Finance Corp | 1.00% |
| New York State Housing Finance Agency | 0.94% |
| Main Street Natural Gas Inc | 0.92% |
| Chandler Industrial Development Authority | 0.86% |
TSSIX Prospectus and SEC Filings
Official Thornburg Strategic Municipal Income Fund filings on SEC EDGAR — prospectus, portfolio holdings and annual reports.
- Prospectus (485BPOS) — filed 2026-01-28
- Prospectus (485BPOS) — filed 2026-01-27
- Prospectus supplement (497) — filed 2025-01-31
- Portfolio holdings (N-PORT) — filed 2026-08-24
- Portfolio holdings (N-PORT) — filed 2026-05-26
- Portfolio holdings (N-PORT) — filed 2026-02-20
- Annual census (N-CEN) — filed 2025-12-02
- Annual census (N-CEN) — filed 2024-12-02
Related Funds
Other Long Municipal - National 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.