T. Rowe Price QM U.S. Bond Index Fund
U.S. bond index fund · tracks Bloomberg U.S. Aggregate Bond Index
As of its 2026 Q2 report, T. Rowe Price QM U.S. Bond Index Fund held 1,604 positions with $2.38B in net assets. Its ten largest holdings made up 15.8% of the fund. Over the 12 months to May 2026, PBDIX returned 5.1%, with dividends reinvested. In 2026 Q3 it added 108 new positions and exited 59.
The fund seeks to provide a total return that matches or incrementally exceeds the performance of the U.S. investment-grade bond market.
The fund tracks the Bloomberg U.S. Aggregate Bond Index by holding a representative sample of investment-grade U.S. bonds across government, agency, mortgage-backed, asset-backed, and corporate segments, rather than replicating the full index. The adviser uses quantitative models to adjust sector and duration positioning relative to the index in pursuit of modest outperformance, which may result in the fund's risk profile diverging from the index. The fund employs interest rate futures, Treasury-backed securities on forward commitment, and credit default swap indexes to manage duration and credit exposure.
What you own
| Company | Weight | Value | Shares |
|---|---|---|---|
TRPGRIAT. Rowe Price Government Reserve Fund | 3.64% | $86.65M | — |
US TREASURY N/B 3.88% · due 2030-04-30 | 2.45% | $58.26M | — |
US TREASURY N/B 4.50% · due 2029-05-31 | 2.25% | $53.57M | — |
US TREASURY N/B 4.13% · due 2029-11-30 | 1.24% | $29.51M | — |
US TREASURY N/B 3.63% · due 2030-10-31 | 1.21% | $28.78M | — |
US TREASURY N/B 4.38% · due 2029-12-31 | 1.16% | $27.60M | — |
US TREASURY N/B 4.13% · due 2027-10-31 | 1.05% | $24.96M | — |
US TREASURY N/B 4.75% · due 2055-05-15 | 0.97% | $23.17M | — |
US TREASURY N/B 4.25% · due 2034-11-15 | 0.97% | $22.99M | — |
US TREASURY N/B 3.63% · due 2030-12-31 | 0.90% | $21.35M | — |
The 200 largest of 1,604 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 | 61.56% |
| Securitized | 37.22% |
| Cash & short-term | 4.02% |
| Derivatives | 0.09% |
Derivatives are shown at market value, not notional exposure.
By sector
- Securitized
- 36.2%
- Government
- 31.3%
- Other
- 8.2%
- Financials
- 5.4%
- 12 other sectors
- 18.8%
- Securitized
- 36.2%
- Government
- 31.3%
- Other
- 8.2%
- Financials
- 5.4%
- Cash
- 4.5%
- International
- 3.2%
- Utilities
- 2.4%
- Health Care
- 1.8%
- Information Technology
- 1.3%
- Industrials
- 1.3%
- Communication Services
- 1.1%
- Energy
- 0.9%
- Real Estate
- 0.8%
- Consumer Discretionary
- 0.7%
- Consumer Staples
- 0.4%
- Materials
- 0.3%
How it has done
PBDIX share class · total returns with dividends reinvested
Volatility over the last 12 months: 3.33%. Past returns are a record, not a forecast.
Jun 2026 and Jul 2026 have been filed since the trailing figures were struck, so they are not in the table above or the curve — every figure here shares one cut-off, which is what makes them comparable with other funds.
The 3 share classes hold the same portfolio
| Share class | Expense ratio | 1 year | 3 years | 5 years | Worst fall |
|---|---|---|---|---|---|
| — | +5.06% | +12.17% | +0.17% | -5.16% | |
| — | +5.33% | +13.00% | +1.37% | -5.05% | |
| — | +5.18% | +12.69% | +0.77% | -5.10% |
These classes hold the same portfolio, so the 1.20pp spread over 5 years is the cost difference between them — roughly 0.24pp a year — not a difference in what they own.
Fees & fund details
T. Rowe Price QM U.S. Bond Index Fund 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
- Portfolio turnover
- 67.00% a year · as of 2025 Q4
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.
108 new· the largest 4
59 exited· the largest 3
Debt profile
What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-04-30
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 | 87.4% |
| Floating rate | 12.6% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 2.1% |
| 1-3y | 10.2% |
| 3-5y | 22.8% |
| 5-10y | 16.6% |
| 10y+ | 48.4% |
These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.
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 about half 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 | 63% |
| Credit spreads | 37% |
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 | +3.38 yr |
| High yield | +0.00 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 | 0.49 yr | 8% |
| 5 yr | 1.76 yr | 30% |
| 10 yr | 2.15 yr | 37% |
| 30 yr | 1.46 yr | 25% |
| 3 mo | 0.01 yr | 0% |
| 1 yr | 0.30 yr | 9% |
| 5 yr | 1.48 yr | 44% |
| 10 yr | 1.30 yr | 39% |
| 30 yr | 0.29 yr | 8% |
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 | +0.01 | +0.00 | $1.6k | $0 |
| 1 yr | +0.49 | +0.30 | +0.00 | $71.4k | $346 |
| 5 yr | +1.76 | +1.48 | +0.00 | $351.7k | $531 |
| 10 yr | +2.15 | +1.30 | +0.00 | $310.3k | $0 |
| 30 yr | +1.46 | +0.29 | +0.00 | $68.2k | $0 |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
A newer credit-spread reading (2026Q3) is on file. This page holds one quarter across every figure on it, so that one appears here next quarter.
Understand how this fund fits with the rest.
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