iShares U.S. Securitized Bond Index Fund
BlackRock Funds
Fund classification
Classified from what the fund holds · as of 2026 Q2
iShares U.S. Securitized Bond Index Fund is a U.S. bond index fund that tracks the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index.
- Asset class
- Bonds
- Region
- United States
- Management
- Index (passive)
- Fund type
- Open-end fund
- Credit quality
- Investment grade
- Rate sensitivity
- Intermediate duration
Fund profile
As filed in the prospectus · 2026 Q1
The investment objective of iShares U.S. Securitized Bond Index Fund (the Fund), a series of BlackRock Funds SM (the Trust), is to seek to provide investment results that correspond to the total return performance of fixed-income securities, in aggregate, as represented by the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index (or the Underlying Index).
The fund tracks the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index using sampling techniques designed to approximate the index's total return, holding a broad portfolio of investment-grade mortgage-backed, asset-backed, and commercial mortgage-backed securities. Because the fund samples rather than fully replicates the index, its returns may diverge from the benchmark. The fund may use derivatives and securities lending to manage liquidity.
| Share class | Gross | Net |
|---|---|---|
| C000234051 | 0.13% | 0.01% |
Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.
Portfolio turnover 243.00% · as of 2026 Q1
Allocation
Asset groups · long / short shown separately, never netted · 2026 Q2
| Securitized | 98.24% |
| Cash & short-term | 8.22% |
| Bonds | 0.21% |
These positions come to 106.67% of the fund's net assets. This counts only what the fund reported holding — the holdings disclosure covers assets, not liabilities such as borrowings — so it is not expected to reconcile to 100%.
Latest quarter
What changed since the fund's previous filing
Largest new: UMBS, TBA ×4, Government National Mortgage Association ×3, Freddie Mac
Largest exited: UMBS, TBA ×6, Government National Mortgage Association ×2
Return profile
Total return as filed — price change plus distributions reinvested · trailing figures to Apr 2026
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 | 97.9% |
| Floating rate | 2.1% |
Share of the fund's debt value in each maturity band, shortest first.
| <1y | 0.0% |
| 1-3y | 0.9% |
| 3-5y | 2.5% |
| 5-10y | 3.3% |
| 10y+ | 93.3% |
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 nearly 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 | 51% |
| Credit spreads | 49% |
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 | +5.38 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.
| 1 yr | 0.42 yr | 8% |
| 5 yr | 1.98 yr | 36% |
| 10 yr | 2.16 yr | 39% |
| 30 yr | 0.96 yr | 17% |
3 mo is NEGATIVE (-0.01 yr) — a deliberate hedge at that point on the curve, so it is not part of the band above.
| 3 mo | 0.02 yr | 0% |
| 1 yr | 0.07 yr | 1% |
| 5 yr | 3.95 yr | 73% |
| 10 yr | 1.35 yr | 25% |
| 30 yr | 0.01 yr | 0% |
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 | +0.02 | $152 | $10.0k |
| 1 yr | +0.42 | +0.07 | +0.00 | $37.6k | $0 |
| 5 yr | +1.98 | +3.95 | +0.00 | $2.22m | $0 |
| 10 yr | +2.16 | +1.35 | +0.00 | $759.4k | $0 |
| 30 yr | +0.96 | +0.01 | +0.00 | $4.3k | $0 |
Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.
Holdings
By % of NAV · equity positions carry filed share counts · every resolvable issuer links to its company page
| Ticker | Issuer | %NAV | Value | Shares |
|---|---|---|---|---|
| — | BLACKROCK CASH FUNDS | 8.22% | $460.89M | — |
| — | Fannie Mae2.00% · due 2051-10-01 | 1.09% | $60.95M | — |
| — | Fannie Mae2.50% · due 2052-01-01 | 0.88% | $49.54M | — |
| — | Fannie Mae2.00% · due 2051-11-01 | 0.85% | $47.87M | — |
| — | Freddie Mac2.00% · due 2051-05-01 | 0.82% | $45.95M | — |
| — | Government National Mortgage Association2.50% · due 2051-05-20 | 0.65% | $36.39M | — |
| — | UMBS, TBA2.00% · due 2041-05-01 | 0.63% | $35.32M | — |
| — | UMBS, TBA3.50% · due 2056-05-01 | 0.57% | $32.06M | — |
| — | Government National Mortgage Association2.00% · due 2052-01-20 | 0.53% | $29.81M | — |
| — | Government National Mortgage Association5.00% · due 2056-05-20 | 0.51% | $28.32M | — |
Top 10 positions are 14.75% of net assets, top 25 21.55%, across 57 issuers.
See more of this fund's book
More positions with filed share counts, and the quarter-over-quarter change list rather than the largest few — free with an account, no card required.
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