U.S. Total Bond Index Master Portfolio
Master Investment Portfolio
Index fund
Expense ratio
Net assets1
$3.65B
Holdings1
9742
Category
Taxable Bond
Return

Top holdings

As of March 31, 2026 · N-PORT
SecurityTickerValue% of fund
BlackRock Cash Funds: Institutional, SL Agency Shares BISXX $182.84M 5.01%
BlackRock Cash Funds: Treasury, SL Agency Shares $120.49M 3.30%
US TREASURY N/B $20.32M 0.56%
US TREASURY N/B $19.23M 0.53%
US TREASURY N/B $17.38M 0.48%
US TREASURY N/B $17.17M 0.47%
US TREASURY N/B $17.06M 0.47%
US TREASURY N/B $16.76M 0.46%
US TREASURY N/B $16.72M 0.46%
US TREASURY N/B $16.44M 0.45%
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Allocation by sector

As of March 31, 2026 · N-PORT
View portfolio breakdown →

Portfolio moves

Dec 31, 2025 → Mar 31, 2026
Opened
476
Exited
323
Increased
40
Decreased
1744
Unchanged
7482

How many positions this fund opened, exited, grew, trimmed, or left unchanged between its two most recent N-PORT snapshots — net changes between point-in-time reports, not a trade log.

View portfolio moves →

Similar funds

Funds whose portfolios most overlap this one, by weight

Advisers

As of December 31, 2025 · N-CEN
FirmRole
BlackRock Fund Advisors Adviser

Footnotes

  1. Net assets and holdings count as of March 31, 2026, from the fund's N-PORT filing.

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