Vanguard Mortgage-Backed Secs Idx Fund Inst (VMBIX)
25.02
+0.04
(+0.16%)
USD |
Aug 24 2026
Returns Chart
Key Stats
| Net Expense Ratio | Total Assets Under Management | Weighted Average Dividend Yield | Turnover Ratio (Generic) |
|---|---|---|---|
| 0.02% | 17.29B | -- | 91.00% |
| 1 Year Fund Level Flows | 1 Year Total Returns (Daily) | Annualized Total Returns Since Inception (Daily) | Max Drawdown (Since Inception) |
| 959.98M | 3.64% |
Basic Info
| Investment Strategy | |
| The Fund seeks to track the performance of a market-weighted mortgage-backed securities index. The Fund employs an indexing approach to track the Bloomberg Barclays US MBS Float Adjusted Index. The Fund invests by sampling the Index and at least 80% of the Funds assets will be invested in bonds included in the Index. |
| General | |
| Security Type | Mutual Fund |
| Equity Style | -- |
| Broad Asset Class | Taxable Bond |
| Broad Category | Fixed Income |
| Global Peer Group | Bond USD Mortgages |
| Peer Group | U.S. Mortgage Funds |
| Global Macro | Bond HC |
| US Macro | U.S. Government & Treasury Fixed Income Funds |
| YCharts Categorization | -- |
| YCharts Benchmark | -- |
| Prospectus Objective | U.S. Mortgage Funds |
| Fund Owner Firm Name | Vanguard |
| Broad Asset Class Benchmark Index | |
| ^BBUSATR | 100.0% |
Net Fund Flows Versus Peer Group
1 Month
% Rank:
2
-270.86M
Peer Group Low
213.80M
Peer Group High
1 Year
% Rank:
2
959.98M
-2.724B
Peer Group Low
1.175B
Peer Group High
3 Months
% Rank:
2
-390.16M
Peer Group Low
979.72M
Peer Group High
3 Years
% Rank:
95
-7.465B
Peer Group Low
7.400B
Peer Group High
6 Months
% Rank:
2
-469.43M
Peer Group Low
1.107B
Peer Group High
5 Years
% Rank:
18
-17.92B
Peer Group Low
11.53B
Peer Group High
YTD
% Rank:
2
-513.57M
Peer Group Low
1.000B
Peer Group High
10 Years
% Rank:
3
-36.79B
Peer Group Low
26.24B
Peer Group High
Date Unavailable
Risk
Performance Versus Peer Group
Annual Total Returns Versus Peers
As of August 25, 2026.
Asset Allocation
As of July 31, 2026.
| Type | % Net |
|---|---|
| Cash | 0.21% |
| Stock | 0.00% |
| Bond | 93.40% |
| Convertible | 0.00% |
| Preferred | 0.00% |
| Other | 6.39% |
Top 10 Holdings
| Name | % Weight | Price | % Change |
|---|---|---|---|
|
Vanguard Market Liquidity Fund
|
3.60% | -- | -- |
|
Government National Mortgage Association 2 5.5% 01-AUG-2056
|
0.38% | -- | -- |
|
Government National Mortgage Association 2 20-NOV-2054 MB0025
|
0.29% | -- | -- |
|
Government National Mortgage Association 2 20-JAN-2056 MB0871
|
0.29% | -- | -- |
|
Federal National Mortgage Association 5% 01-SEP-2056
|
0.28% | -- | -- |
|
Government National Mortgage Association 2 20-JUN-2056 MB1216
|
0.27% | -- | -- |
|
Federal National Mortgage Association 01-MAR-2056 CC2762
|
0.27% | -- | -- |
|
Government National Mortgage Association 2 20-FEB-2056 MB0936
|
0.27% | -- | -- |
|
Government National Mortgage Association 2 20-NOV-2054 MB0024
|
0.26% | -- | -- |
|
Federal Home Loan Mortgage Corp 01-FEB-2052 SD4155
|
0.25% | -- | -- |
Fees & Availability
| Fees | |
| Actual 12B-1 Fee | -- |
| Actual Management Fee | 0.02% |
| Administration Fee | 235000.0 None |
| Maximum Front Load | -- |
| Maximum Deferred Load | -- |
| Maximum Redemption Fee | -- |
| General Availability | |
| Available for Insurance Product | No |
| Available for RRSP | No |
| Purchase Details | |
| Open to New Investors |
|
| Minimum Initial Investment | 5.00M None |
| Minimum Subsequent Investment | 1.00 None |
Projected Income
| Type | Aug | Sep | Oct | Nov | Dec | Jan | Feb | Mar | Apr | May | Jun | Jul |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Qualified Income
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Normal
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Qualified
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
LT Cap Gains
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Ordinary Income
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Non-Qual
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
ST Cap Gains
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Interest
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Tax-Exempt
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
ROC
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Other
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
|
Total
|
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
As of July 31, 2026.
Basic Info
| Investment Strategy | |
| The Fund seeks to track the performance of a market-weighted mortgage-backed securities index. The Fund employs an indexing approach to track the Bloomberg Barclays US MBS Float Adjusted Index. The Fund invests by sampling the Index and at least 80% of the Funds assets will be invested in bonds included in the Index. |
| General | |
| Security Type | Mutual Fund |
| Equity Style | -- |
| Broad Asset Class | Taxable Bond |
| Broad Category | Fixed Income |
| Global Peer Group | Bond USD Mortgages |
| Peer Group | U.S. Mortgage Funds |
| Global Macro | Bond HC |
| US Macro | U.S. Government & Treasury Fixed Income Funds |
| YCharts Categorization | -- |
| YCharts Benchmark | -- |
| Prospectus Objective | U.S. Mortgage Funds |
| Fund Owner Firm Name | Vanguard |
| Broad Asset Class Benchmark Index | |
| ^BBUSATR | 100.0% |
Fundamentals
| General | |
| Distribution Yield | -- |
| Dividend Yield TTM (8-24-26) | 4.24% |
| 30-Day SEC Yield (7-31-26) | 4.25% |
| 7-Day SEC Yield | -- |
| Number of Holdings | 5175 |
| Bond | |
| Yield to Maturity (7-31-26) | 5.25% |
| Effective Duration | 5.30 |
| Average Coupon | 3.95% |
| Calculated Average Quality | 1.00 |
| Effective Maturity | 25.74 |
| Nominal Maturity | 25.74 |
| Number of Bond Holdings | 5124 |
As of July 31, 2026
Fund Details
| Key Dates | |
| Inception Date | 10/31/2013 |
| Last Annual Report Date | 8/31/2025 |
| Last Prospectus Date | 2/2/2026 |
| Share Classes | |
| VMBSX | Admiral |
| Attributes | |
| Index Fund |
|
| Inverse Fund | No |
| Leveraged Fund | -- |
| Fund of Funds | No |
| Currency Hedged Fund | -- |
| Socially Responsible Fund | No |
Top Portfolio Holders
| Name | % Weight |
|---|---|
| Portfolio A | 5.00% |
| Portfolio B | 3.50% |
| Portfolio C | 2.25% |
Excel Add-In Codes
| Name: =YCI("M:VMBIX", "name") |
| Broad Asset Class: =YCI("M:VMBIX", "broad_asset_class") |
| Broad Category: =YCI("M:VMBIX", "broad_category_group") |
| Prospectus Objective: =YCI("M:VMBIX", "prospectus_objective") |
| To find the codes for any of our securities and financial metrics, see our Complete Excel Reference. |