iShares U.S. Securitized Bond Index Fund
Data updated: 2026-09-25
C000234051 — iShares U.S. Securitized Bond Index Fund. Long Securitized (MBS/ABS/CMBS) Bond · $5.32B AUM. Holdings, fees, performance and SEC filings.
C000234051 Fund Overview
iShares U.S. Securitized Bond Index Fund is a US mutual fund managed by Blackrock Funds, 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: Blackrock Funds
- Category: Long Securitized (MBS/ABS/CMBS) Bond
- Assets under management: $5.32B
- 1-year return: 5.6%
- SEC CIK: 0000844779
- SEC series ID: S000075207
- Share class ID: C000234051
C000234051 Investment Objective and Strategy
iShares U.S. Securitized Bond Index Fund describes its objective and strategy as follows, from its latest prospectus filed with the SEC by Blackrock Funds.
Investment objective
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).
Principal investment strategy
Under normal circumstances, at least 90% of the value of the Funds assets, plus the amount of any borrowings for investment purposes, is invested in securities comprising the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index, which, for the Fund, are considered bonds. The Fund attempts to achieve, in both rising and falling markets, a correlation of at least 95% between the total return of its net assets before fees and expenses and the total return of the Funds benchmark index, the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index. Notwithstanding the factors described below, perfect (100%) correlation would be achieved if the total return of the Funds net assets, before fees and expenses, increased or decreased exactly as the total return of the Funds benchmark index increased or decreased.
The Funds ability to match its investment performance to the investment performance of its benchmark index may be affected by, among other things, the Funds expenses, the amount of cash and cash equivalents held by the Fund, the manner in which the total return of the Funds benchmark index is calculated, the size of the Funds investment portfolio, and the timing, frequency and size of shareholder purchases and redemptions. The Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index is a capitalization weighted index that measures all U.S. dollar-denominated, investment grade, securitized issues within the Bloomberg U.S. Aggregate Bond Index. Mortgage-backed securities must have a weighted average maturity of at least one year. Commercial mortgage-backed securities and asset-backed securities must have a remaining average life of at least one year.
The index is rebalanced monthly. There were approximately 3,926 fixed-income securities included in the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index as of December 31, 2025. All securities in the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index are rated investment-grade. The Fund will be invested and reinvested primarily in U.S. debt securities with maturities greater than ten years, with the objective of approximating as closely as practicable the total rate of return of the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index. The Fund utilizes sampling techniques that are designed to allow the Fund to duplicate substantially the investment performance of the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index. However, the Fund is not expected to track the Bloomberg U.S. Securitized: MBS, ABS, and CMBS Index with the same degree of accuracy that complete replication of the Bloomberg U.S.
Securitized: MBS, ABS, and CMBS Index would provide. No attempt is made to manage the Fund using economic, financial or market analysis. In addition, at times, the portfolio composition of the Fund may be altered (or rebalanced) to reflect changes in the characteristics of the index that the Fund tracks. The Fund also may engage in futures, forwards and options transactions and other derivative securities transactions and lend its portfolio securities, each of which involves risk. The Fund may use futures contracts, forwards, options and other derivative transactions to manage its short-term liquidity and/or as substitutes for comparable market positions in the securities in its benchmark index. The Fund may also invest in high-quality money market instruments, including shares of money market funds advised by BFA or its affiliates.
C000234051 Holdings
Top 10 holdings of iShares U.S. Securitized Bond Index Fund by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| Blackrock Cash Funds | 7.08% |
| Fannie Mae | 0.89% |
| Fannie Mae | 0.88% |
| Fannie Mae | 0.86% |
| Freddie Mac | 0.82% |
| Government National Mortgage Association | 0.65% |
| Umbs, Tba | 0.63% |
| Umbs, Tba | 0.62% |
| Government National Mortgage Association | 0.53% |
| Government National Mortgage Association | 0.50% |
C000234051 Portfolio Allocation
Asset-class allocation of iShares U.S. Securitized Bond Index Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Securitized | 98.3% |
| Cash & Equivalents | 7.1% |
| Fixed Income | 0.3% |
C000234051 Performance
Total returns for C000234051 (as of 2026-10-01), from SEC filings.
| Period | Total return |
|---|---|
| YTD | 0.5% |
| 1 year | 5.6% |
| 3 years (annualised) | 4.1% |
C000234051 Risk Information
Risk metrics for C000234051, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 3.6%
C000234051 Costs and Fees
C000234051 costs about $1 per $10,000 invested per year in fund expenses.
- Net expense ratio: 0.01%
- Gross expense ratio: 0.13%
- Portfolio turnover: 243%
- Brokerage commissions: 0.00 bps of average net assets (SEC N-CEN)
C000234051 Cashflows
Over the 12 months to 2026-04, iShares U.S. Securitized Bond Index Fund had net inflows of $166.88M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-04 | −$132.39M |
| 2026-03 | −$70.77M |
| 2026-02 | $33.61M |
| 2026-01 | −$30.32M |
| 2025-12 | $53.65M |
| 2025-11 | $20.67M |
C000234051 Debt Constituents
Largest debt holdings of iShares U.S. Securitized Bond Index Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Debt holding | % of net assets |
|---|---|
| Virginia Power Fuel Sec | 0.04% |
| Pg&e Recovery Fnd LLC | 0.04% |
| Sce Recovery Funding LLC | 0.03% |
| Sce Recovery Funding LLC | 0.02% |
| Pg&e Recovery Fnd LLC | 0.02% |
| Pg&e Wildfire Recovery | 0.02% |
| Pg&e Wildfire Recovery | 0.02% |
| Sce Recovery Funding LLC | 0.02% |
| Nyseg Storm Funding LLC | 0.01% |
| Sce Recovery Funding LLC | 0.01% |
C000234051 Prospectus and SEC Filings
Official iShares U.S. Securitized Bond Index Fund filings on SEC EDGAR — prospectus, portfolio holdings and annual reports.
- Prospectus (485BPOS) — filed 2026-02-23
- Prospectus (485BPOS) — filed 2025-02-26
- Prospectus (485BPOS) — filed 2024-02-22
- Portfolio holdings (N-PORT) — filed 2026-09-25
- Portfolio holdings (N-PORT) — filed 2026-06-25
- Portfolio holdings (N-PORT) — filed 2026-03-26
- Annual census (N-CEN) — filed 2026-01-14
- Annual census (N-CEN) — filed 2025-01-13
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.