State Street Aggregate Bond Index Portfolio
U.S. bond index fund · tracks Bloomberg U.S. Aggregate Bond Index
As of its 2026 Q2 report, State Street Aggregate Bond Index Portfolio held 6,798 positions with $6.20B in net assets. Its ten largest holdings made up 7.2% of the fund. The SSAFX share class costs 0.02% a year. Over the 12 months to May 2026, SSAFX returned 5.1%, with dividends reinvested. In 2026 Q2 it added 415 new positions and exited 297.
The State Street Aggregate Bond Index Portfolio (the Aggregate Bond Index Portfolio ? or the Portfolio) seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the U.S. dollar denominated investment grade bond market over the long term.
The fund tracks the Bloomberg U.S. Aggregate Bond Index, which measures the investment-grade U.S. dollar bond market including government, corporate, mortgage pass-through, and asset-backed securities. It uses a sampling strategy, holding a subset of index securities rather than all constituents, to achieve similar risk and return characteristics. Because the fund samples rather than fully replicates the index, its performance may diverge from the index.
What you own
| Company | Weight | Value | Shares |
|---|---|---|---|
GVMXXState Street Global Advisors | 3.69% | $228.54M | — |
United States Treasury 4.13% · due 2036-02-15 | 0.42% | $26.35M | — |
United States Treasury 3.38% · due 2028-02-29 | 0.42% | $26.17M | — |
United States Treasury 3.88% · due 2028-03-31 | 0.40% | $24.88M | — |
United States Treasury 4.25% · due 2034-11-15 | 0.39% | $24.26M | — |
United States Treasury 4.25% · due 2035-08-15 | 0.39% | $24.19M | — |
United States Treasury 4.00% · due 2035-11-15 | 0.39% | $23.89M | — |
United States Treasury 3.50% · due 2027-10-31 | 0.38% | $23.79M | — |
United States Treasury 4.50% · due 2033-11-15 | 0.38% | $23.74M | — |
United States Treasury 4.63% · due 2046-02-15 | 0.36% | $22.56M | — |
The 200 largest of 6,798 holdings, with the share counts as filed, open with a free account.
What the fund is made of
Percentages are of fund net assets. Rounding, liabilities and short positions can make totals differ from 100%.
| Bonds | 73.47% |
| Securitized | 25.09% |
| Cash & short-term | 3.69% |
By sector
- Government
- 48.3%
- Securitized
- 24.5%
- Financials
- 4.8%
- Other
- 4.0%
- 12 other sectors
- 18.4%
- Government
- 48.3%
- Securitized
- 24.5%
- Financials
- 4.8%
- Other
- 4.0%
- Cash
- 3.6%
- International
- 2.6%
- Utilities
- 2.4%
- Health Care
- 1.9%
- Information Technology
- 1.7%
- Communication Services
- 1.4%
- Industrials
- 1.4%
- Consumer Staples
- 0.9%
- Consumer Discretionary
- 0.7%
- Energy
- 0.7%
- Real Estate
- 0.5%
- Materials
- 0.3%
How it has done
SSAFX share class · total returns with dividends reinvested
Volatility over the last 12 months: 3.25%. Past returns are a record, not a forecast.
Jun 2026 has been filed since the trailing figures were struck, so it is not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.
Fees & fund details
State Street Aggregate Bond Index Portfolio is a U.S. bond index fund that tracks the Bloomberg U.S. Aggregate Bond Index.
- Asset class
- Bonds
- Region
- United States
- Management
- Index (passive)
- Fund type
- Open-end fund
- Credit quality
- Investment grade
- Rate sensitivity
- Intermediate duration
- Features
- Master-feeder
- Expense ratio, by class
- 0.02%· SSAFX 0.02%
- Portfolio turnover
- 17.00% a year · as of 2026 Q2
Turnover is how much of the portfolio was replaced in a year.
Classified from what the fund holds, not from its name · 2026 Q2. The summary is a paraphrase of the prospectus; the objective is verbatim.
What changed this quarter
Positions that entered or left the fund since its previous filing. Positions that were only resized are not listed.
415 new· the largest 2
297 exited· the largest 2
Debt profile
What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-06-30
Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.
| Fixed rate | 99.5% |
| Floating rate | 0.5% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 0.0% |
| 1-3y | 21.7% |
| 3-5y | 17.0% |
| 5-10y | 18.8% |
| 10y+ | 42.6% |
Based on what filers reported; a filer that never reported a flag also reads as none.
Risk profile
Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2
Most of this fund’s sensitivity is to interest rates, with credit spreads carrying a small fraction as much.
Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.
| Interest rates | 75% |
| Credit spreads | 25% |
Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.
Share of the fund's spread duration carried by each credit tier.
| Investment grade | +1.93 yr |
| High yield | +0.02 yr |
Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.
| 3 mo | 0.01 yr | 0% |
| 1 yr | 0.66 yr | 11% |
| 5 yr | 1.68 yr | 28% |
| 10 yr | 2.29 yr | 39% |
| 30 yr | 1.27 yr | 21% |
| 3 mo | 0.00 yr | 0% |
| 1 yr | 0.19 yr | 10% |
| 5 yr | 0.56 yr | 29% |
| 10 yr | 0.74 yr | 38% |
| 30 yr | 0.47 yr | 24% |
The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.
Show the numbers
| Tenor | Rate yrs | IG yrs | HY yrs | IG $/bp | HY $/bp |
|---|---|---|---|---|---|
| 3 mo | +0.01 | +0.00 | +0.00 | $1.9k | $30 |
| 1 yr | +0.66 | +0.18 | +0.00 | $113.5k | $2.3k |
| 5 yr | +1.68 | +0.55 | +0.01 | $339.9k | $7.4k |
| 10 yr | +2.29 | +0.73 | +0.01 | $454.2k | $4.1k |
| 30 yr | +1.27 | +0.47 | +0.00 | $289.6k | $577 |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
Understand how this fund fits with the rest.
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