TSIIX — Thornburg Strategic Income Fund
Data updated: 2026-08-24
TSIIX — Thornburg Strategic Income Fund. Long Total / Aggregate Bond · $10.09B AUM · 0.60% expense ratio. Holdings, fees, performance and SEC filings.
TSIIX Fund Overview
TSIIX — Thornburg Strategic Income Fund is a US mutual fund managed by Thornburg Investment Trust, categorised as Long Total / Aggregate 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 Total / Aggregate Bond
- Assets under management: $10.09B
- 1-year return: 4.5%
- Ticker: TSIIX
- SEC CIK: 0000816153
- SEC series ID: S000020097
- Share class ID: C000056391
TSIIX Holdings
Top 10 holdings of Thornburg Strategic Income Fund by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| Thornburg Capital Management Fund | 2.91% |
| United States Treasury | 1.91% |
| United States Treasury | 1.33% |
| United States Treasury | 1.15% |
| United States Treasury | 1.02% |
| Government National Mortgage Association | 0.76% |
| United States Treasury | 0.66% |
| United States Treasury | 0.63% |
| Government National Mortgage Association | 0.61% |
| United States Treasury | 0.50% |
TSIIX Portfolio Allocation
Asset-class allocation of Thornburg Strategic Income Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Fixed Income | 57.4% |
| Securitized | 36.7% |
| Equity | 3.4% |
| Loans | 2.5% |
| Cash & Equivalents | 0.6% |
TSIIX Performance
Total returns for TSIIX (as of 2026-09-01), from SEC filings.
| Period | Total return |
|---|---|
| YTD | 1.2% |
| 1 year | 4.5% |
| 3 years (annualised) | 5.9% |
| 5 years (annualised) | 3.1% |
TSIIX Risk Information
Risk metrics for TSIIX, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 2.1%
TSIIX Costs and Fees
TSIIX costs about $60 per $10,000 invested per year in fund expenses.
- Net expense ratio: 0.60%
- Gross expense ratio: 0.73%
- Portfolio turnover: 30%
- Brokerage commissions: 0.01 bps of average net assets (SEC N-CEN)
TSIIX Cashflows
Over the 12 months to 2026-06, Thornburg Strategic Income Fund had net inflows of $404.66M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-06 | −$54.73M |
| 2026-05 | $32.38M |
| 2026-04 | −$41.68M |
| 2026-03 | −$106.40M |
| 2026-02 | $48.52M |
| 2026-01 | −$24.09M |
TSIIX Debt Constituents
Largest debt holdings of Thornburg Strategic Income Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| United States Treasury | 1.91% |
| United States Treasury | 1.33% |
| United States Treasury | 1.15% |
| United States Treasury | 1.02% |
| United States Treasury | 0.66% |
| United States Treasury | 0.63% |
| United States Treasury | 0.50% |
| United States Treasury | 0.40% |
| United States Treasury | 0.34% |
| Cobank Acb | 0.34% |
TSIIX Prospectus and SEC Filings
Official Thornburg Strategic 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 (485BPOS) — filed 2025-01-28
- 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 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.