LMBSX Performance — Western Asset Mortgage Total Return Fund, Class IS
Data updated: 2026-08-26
LMBSX returned +1.90% year to date and +5.55% over one year to Jun 2026. Annualised returns are +5.47% over 3 years and +0.71% over 5 years. The fund beat its Intermediate Securitized Bond category average: $100 invested three years ago grew to $117, against $116 for the category, and to $106 over one year, against $105. Volatility over the past three years was 6.14% a year. In the 12 months to Jun 2026 the fund lost a net $35.2M, and assets reached $328.10M.
LMBSX Growth of $100
What $100 invested in Western Asset Mortgage Total Return Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the Intermediate Securitized Bond category average over the same months.
| Period | LMBSX | Category average |
|---|---|---|
| 1 year (Jul 2025 – Jun 2026) | $106 | $105 |
| 3 years (Jul 2023 – Jun 2026) | $117 | $116 |
| 5 years (Jul 2021 – Jun 2026) | $104 | $105 |
| Since data start (Jul 2019 – Jun 2026) | $109 | $113 |
LMBSX Trailing Returns
Total returns to Jun 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +1.90% |
| 1 year | +5.55% |
| 3 years (annualised) | +5.47% |
| 5 years (annualised) | +0.71% |
LMBSX Annual Returns
Calendar-year total returns of Western Asset Mortgage Total Return Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–Jun) | +1.90% |
| 2025 | +8.10% |
| 2024 | +3.52% |
| 2023 | +4.30% |
| 2022 | −13.52% |
| 2021 | +1.16% |
| 2020 | +2.57% |
| 2019 (Jul–Dec) | +1.83% |
LMBSX 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% | +1.7% | −1.7% | +0.5% | +0.2% | +0.6% | — | — | — | — | — | — |
| 2025 | +0.8% | +2.7% | −0.4% | 0.0% | −0.5% | +1.8% | −0.2% | +1.7% | +0.7% | +0.4% | +1.0% | −0.1% |
| 2024 | +0.4% | −1.3% | +1.0% | −2.5% | +1.7% | +1.4% | +2.5% | +1.3% | +1.3% | −2.5% | +1.4% | −1.2% |
| 2023 | +3.7% | −2.9% | +2.2% | +0.7% | −1.4% | −0.8% | −0.2% | −0.3% | −3.4% | −2.4% | +4.9% | +4.5% |
| 2022 | −1.1% | −1.0% | −2.7% | −2.9% | +0.3% | −1.4% | +2.6% | −3.2% | −5.3% | −2.5% | +3.9% | −0.9% |
| 2021 | +0.1% | −0.2% | −0.2% | +0.6% | −0.2% | +0.4% | +1.1% | +0.2% | −0.4% | −0.2% | 0.0% | +0.1% |
| 2020 | +0.9% | +1.1% | −4.7% | +0.9% | +0.8% | +1.4% | +0.5% | +0.1% | +0.5% | 0.0% | +0.3% | +1.0% |
| 2019 | — | — | — | — | — | — | +0.4% | +1.3% | +0.1% | +0.2% | −0.2% | +0.1% |
LMBSX Risk
Risk measures from monthly returns over Jul 2023 – Jun 2026.
- 3-year volatility (annualised): 6.14%
- 3-year Sharpe ratio: 0.16 (vs 4.5% risk-free rate)
- Best month: +4.89% (Nov 2023)
- Worst month: −3.36% (Sep 2023)
LMBSX Fund Flows
Monthly money in and out of Western Asset Mortgage Total Return Fund, from SEC Form N-PORT.
- 12-month net flow: −$35.2M
- 12-month gross sales (incl. reinvestments): $40.4M
- Sales ÷ redemptions: 0.53×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| Jun 2026 | $2.6M | $5.7M | −$3.1M |
| May 2026 | $3.1M | $6.4M | −$3.3M |
| Apr 2026 | $3.0M | $6.7M | −$3.7M |
| Mar 2026 | $3.5M | $6.0M | −$2.5M |
| Feb 2026 | $3.5M | $5.0M | −$1.5M |
| Jan 2026 | $3.2M | $10.1M | −$6.8M |
| Dec 2025 | $3.2M | $8.4M | −$5.2M |
| Nov 2025 | $3.0M | $5.1M | −$2.1M |
| Oct 2025 | $5.2M | $5.5M | −$318K |
| Sep 2025 | $3.7M | $5.6M | −$1.9M |
| Aug 2025 | $2.9M | $5.4M | −$2.5M |
| Jul 2025 | $3.4M | $5.7M | −$2.3M |
LMBSX Assets Under Management
Net assets of Western Asset Mortgage Total Return Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-06-30 | $328.10M |
| 2026-03-31 | $338.47M |
| 2025-12-31 | $351.94M |
| 2025-09-30 | $359.68M |
| 2025-06-30 | $363.34M |
| 2025-03-31 | $371.79M |
| 2024-12-31 | $375.00M |
| 2024-09-30 | $407.27M |
| 2024-06-28 | $402.28M |
| 2024-03-28 | $416.64M |
| 2023-12-29 | $450.75M |
| 2023-09-29 | $450.62M |
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.