LWMSX — Western Asset Mortgage Backed Securities Fund
Data updated: 2026-05-28
LWMSX — Western Asset Mortgage Backed Securities Fund data: holdings, portfolio allocation, expenses, performance, cashflows, risk and SEC filings. Long Securitized (MBS/ABS/CMBS) Bond · $338.47M AUM · 1.65% expense ratio · 4.3% 1-yr return. From SEC regulatory filings.
LWMSX Fund Overview
LWMSX — Western Asset Mortgage Backed Securities Fund is a US mutual fund managed by Legg Mason Partners Income Trust, categorised as Long Securitized (MBS/ABS/CMBS) Bond. ABC INVEST provides holdings, performance, costs, cashflows, risk data, prospectus documents and SEC filings, sourced from SEC filings.
- Type: US mutual fund
- Manager: Legg Mason Partners Income Trust
- Category: Long Securitized (MBS/ABS/CMBS) Bond
- Assets under management: $338.47M
- 1-year return: 4.3%
- Ticker: LWMSX
- SEC CIK: 0000764624
- SEC series ID: S000016649
- Share class ID: C000088509
LWMSX Holdings
Top 10 holdings of Western Asset Mortgage Backed Securities Fund by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| Federal National Mortgage Association | 6.68% |
| Federal National Mortgage Association | 6.12% |
| Federal National Mortgage Association | 6.05% |
| Federal National Mortgage Association | 4.45% |
| Federal National Mortgage Association | 4.31% |
| Government National Mortgage Association | 3.48% |
| Government National Mortgage Association | 2.60% |
| Federal National Mortgage Association | 2.57% |
| Government National Mortgage Association | 2.11% |
| Government National Mortgage Association | 2.08% |
LWMSX Portfolio Allocation
Asset-class allocation of Western Asset Mortgage Backed Securities Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Securitized | 141.9% |
| Fixed Income | 2.2% |
| Equity | 1.2% |
| Cash & Equivalents | 0.6% |
| Real Estate | 0.2% |
LWMSX Performance
Total returns for LWMSX (as of 2026-08-01), from SEC filings.
| Period | Total return |
|---|---|
| YTD | 0.3% |
| 1 year | 4.3% |
| 3 years (annualised) | 3.4% |
| 5 years (annualised) | -0.5% |
LWMSX Risk Information
Risk metrics for LWMSX, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 3.6%
LWMSX Costs and Fees
LWMSX costs about $165 per $10,000 invested per year in fund expenses.
- Net expense ratio: 1.65%
- Gross expense ratio: 1.65%
- Portfolio turnover: 198%
- Brokerage commissions: 0.38 bps of average net assets (SEC N-CEN)
LWMSX Cashflows
Over the 12 months to 2026-03, Western Asset Mortgage Backed Securities Fund had net outflows of $33.10M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-03 | −$2.48M |
| 2026-02 | −$1.51M |
| 2026-01 | −$6.83M |
| 2025-12 | −$5.18M |
| 2025-11 | −$2.07M |
| 2025-10 | −$317.85K |
LWMSX Debt Constituents
Largest debt holdings of Western Asset Mortgage Backed Securities Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| Full House Resorts Inc. | 0.32% |
| Expand Energy Corp. | 0.32% |
| Lithia Motors Incorporated | 0.28% |
| Carnival Corporation | 0.26% |
| Venture Global Calcasieu Pass LLC | 0.26% |
| Royal Caribbean Group | 0.25% |
| Arbor Realty Senior Incorporated | 0.19% |
| ZF North America Capital, Inc. | 0.18% |
| Arbor Realty Senior Incorporated | 0.12% |
| CHS/Community Health Systems Inc | 0.08% |
LWMSX Prospectus and SEC Filings
Official Western Asset Mortgage Backed Securities Fund filings on SEC EDGAR — prospectus, portfolio holdings and annual reports.
Related Funds
Other Long Securitized (MBS/ABS/CMBS) 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.