MBB Top Holdings & Constituents
MBB, offered by iShares, holds 11153 reported positions across $39.3B in assets. Its largest holdings are BLACKROCK CASH FUNDS (5.90%), Freddie Mac (1.07%), and Government National Mortgage Association (1.00%). The 5 biggest positions account for 9.11% of reported assets. The table below lists every reported holding with its portfolio weight and market value in US dollars — open any constituent to research its own performance.
| Position | Weight | Market Value |
|---|---|---|
— BLACKROCK CASH FUNDS | 5.90% | $2.35B |
— Freddie Mac | 1.07% | $427.59M |
— Government National Mortgage Association | 1.00% | $399.52M |
— UMBS, TBA | 0.57% | $227.79M |
— Government National Mortgage Association | 0.56% | $221.29M |
Holdings data comes from the latest SEC Form N-PORT-P filing for this fund, covering the reporting period ended Feb 28, 2026. Market values are reported in US dollars, and each weight represents the position's share of reported fund assets. Cash, derivatives, and rounding can mean displayed weights do not total 100%. Funds rebalance and file on a schedule, so this page may not reflect intraday or post-filing changes.