TSSIX Performance — Thornburg Strategic Municipal Income Fund, Class I
Data updated: 2026-08-24
TSSIX returned +2.78% year to date and +6.66% over one year to Jun 2026. Annualised returns are +4.63% over 3 years and +1.54% over 5 years. The fund beat its Intermediate Municipal Bond category average: $100 invested three years ago grew to $115, against $111 for the category, and to $107 over one year, against $106. Volatility over the past three years was 4.51% a year. In the 12 months to Jun 2026 the fund took in a net $55.6M, and assets reached $428.33M.
TSSIX Growth of $100
What $100 invested in Thornburg Strategic Municipal Income Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the Intermediate Municipal Bond category average over the same months.
| Period | TSSIX | Category average |
|---|---|---|
| 1 year (Jul 2025 – Jun 2026) | $107 | $106 |
| 3 years (Jul 2023 – Jun 2026) | $115 | $111 |
| 5 years (Jul 2021 – Jun 2026) | $108 | $105 |
| Since data start (Jul 2019 – Jun 2026) | $116 | $112 |
TSSIX Trailing Returns
Total returns to Jun 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +2.78% |
| 1 year | +6.66% |
| 3 years (annualised) | +4.63% |
| 5 years (annualised) | +1.54% |
TSSIX Annual Returns
Calendar-year total returns of Thornburg Strategic Municipal Income Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–Jun) | +2.78% |
| 2025 | +4.24% |
| 2024 | +3.11% |
| 2023 | +6.12% |
| 2022 | −8.09% |
| 2021 | +1.52% |
| 2020 | +4.00% |
| 2019 (Jul–Dec) | +1.72% |
TSSIX Monthly Returns
Monthly total returns as reported on SEC Form N-PORT.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +0.6% | +1.2% | −1.8% | +1.1% | +0.5% | +1.1% | — | — | — | — | — | — |
| 2025 | +0.5% | +1.0% | −1.1% | −0.5% | +0.1% | +0.5% | −0.3% | +0.7% | +2.2% | +1.0% | +0.2% | −0.1% |
| 2024 | −0.3% | +0.4% | +0.6% | −0.9% | +0.1% | +1.3% | +1.0% | +0.8% | +0.8% | −1.1% | +1.3% | −1.0% |
| 2023 | +2.3% | −1.6% | +1.6% | 0.0% | −0.7% | +0.8% | +0.4% | −0.9% | −2.2% | −0.8% | +5.2% | +2.0% |
| 2022 | −2.3% | −0.4% | −2.9% | −2.4% | +0.9% | −1.4% | +2.0% | −1.6% | −3.3% | −0.9% | +3.7% | +0.3% |
| 2021 | +0.8% | −1.1% | +0.4% | +0.6% | +0.3% | +0.3% | +0.6% | −0.2% | −0.5% | −0.5% | +0.8% | 0.0% |
| 2020 | +1.6% | +1.2% | −4.2% | −1.5% | +2.3% | +1.6% | +1.7% | −0.1% | −0.1% | −0.2% | +1.2% | +0.7% |
| 2019 | — | — | — | — | — | — | +0.7% | +1.1% | −0.6% | +0.1% | +0.1% | +0.2% |
TSSIX Risk
Risk measures from monthly returns over Jul 2023 – Jun 2026.
- 3-year volatility (annualised): 4.51%
- 3-year Sharpe ratio: 0.03 (vs 4.5% risk-free rate)
- Best month: +5.23% (Nov 2023)
- Worst month: −2.18% (Sep 2023)
TSSIX Fund Flows
Monthly money in and out of Thornburg Strategic Municipal Income Fund, from SEC Form N-PORT.
- 12-month net flow: $55.6M
- 12-month gross sales (incl. reinvestments): $140.8M
- Sales ÷ redemptions: 1.65×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| Jun 2026 | $7.5M | $4.9M | $2.6M |
| May 2026 | $16.7M | $6.0M | $10.7M |
| Apr 2026 | $8.0M | $5.1M | $2.8M |
| Mar 2026 | $10.1M | $6.4M | $3.7M |
| Feb 2026 | $10.5M | $5.9M | $4.7M |
| Jan 2026 | $11.6M | $12.0M | −$390K |
| Dec 2025 | $17.2M | $4.9M | $12.3M |
| Nov 2025 | $10.4M | $4.5M | $5.9M |
| Oct 2025 | $10.3M | $6.1M | $4.1M |
| Sep 2025 | $14.2M | $16.9M | −$2.7M |
| Aug 2025 | $12.8M | $7.1M | $5.6M |
| Jul 2025 | $11.6M | $5.4M | $6.2M |
TSSIX Assets Under Management
Net assets of Thornburg Strategic Municipal Income Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-06-30 | $428.33M |
| 2026-03-31 | $405.33M |
| 2025-12-31 | $401.43M |
| 2025-09-30 | $378.93M |
| 2025-06-30 | $363.83M |
| 2025-03-31 | $363.54M |
| 2024-12-31 | $358.41M |
| 2024-09-30 | $321.64M |
| 2024-06-30 | $308.54M |
| 2024-03-31 | $309.88M |
| 2023-12-31 | $311.25M |
| 2023-09-30 | $294.22M |
For information only. Not investment advice: figures are as reported in SEC filings and may contain errors or be out of date. Past performance does not guarantee future results.