BIV vs MBB: Holdings Overlap
BIVVanguard Intermediate-term Bond Index Fund
Vanguard · 2340 holdings · $28.9B · as of 2026-03-31
iShares · 11144 holdings · $39.1B · as of 2026-05-31
Holdings snapshots are 61 days apart (BIV: 2026-03-31, MBB: 2026-05-31). Weights and index membership change between snapshots, so the true current overlap is typically higher than shown. For funds tracking the same index, the gap can be 5–15 points.
How similar are BIV and MBB?
Vanguard Intermediate-term Bond Index Fund (BIV, by Vanguard) holds 2340 positions; iShares MBS ETF (MBB, by iShares) holds 11144. They have 0 holdings in common, and by portfolio weight the two funds are 0.0% identical. In practical terms the pair is essentially distinct, holding almost none of the same securities.
- Overlap by Weight
- 0.0%Sum of the smaller weight of each shared holding
- Shared Holdings
- 0BIV holds 2340 · MBB holds 11144
- Weight in Shared Holdings
- BIV 0%·MBB 0%Share of each fund's weight in stocks both funds own
Based on each fund's latest official holdings. How is this calculated?
What makes each fund different
Only in BIV
2340 of 2340 positions (98.8% of the fund) are not held by MBB. Showing the top 30 by weight.
- U.S. Treasury Notes2.29%
- U.S. Treasury Notes2.20%
- U.S. Treasury Notes2.19%
- U.S. Treasury Notes2.18%
- U.S. Treasury Notes2.06%
- U.S. Treasury Notes2.06%
Only in MBB
11144 of 11144 positions (98.1% of the fund) are not held by BIV. Showing the top 30 by weight.
- Freddie Mac Pool1.05%
- Ginnie Mae0.95%
- Uniform Mortgage-Backed Security, TBA0.83%
- Ginnie Mae0.67%
- Uniform Mortgage-Backed Security, TBA0.64%
- Ginnie Mae II Pool0.55%
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| BIV | -0.2% | -0.3% | +2.0% | +4.6% | -0.1% | +1.7% | 4.31% |
| MBB | -0.2% | +0.4% | +3.9% | +4.7% | +0.3% | +1.2% | 4.33% |
Total returns including dividends, from adjusted daily closes as of 2026-08-07. 3Y/5Y/10Y are annualized. Yield is trailing-12-month distributions over the last close. Past performance does not predict future results.
Project the growth of $10,000 in BIV vs MBB →
Shared Holdings(0)
These two funds have no holdings in common.
Frequently Asked Questions
How much do BIV and MBB overlap?
BIV and MBB overlap by 0.0% of portfolio weight. They share 0 holdings (BIV holds 2340 positions and MBB holds 11144), based on each fund's latest SEC-reported holdings.
Is it redundant to own both BIV and MBB?
The two portfolios are 0.0% identical by weight. Owning both is genuine diversification: the funds hold almost none of the same securities.
What does BIV own that MBB doesn't?
2340 positions (98.8% of BIV) are unique to BIV, led by U.S. Treasury Notes, U.S. Treasury Notes and U.S. Treasury Notes. In the other direction, 11144 positions (98.1% of MBB) are unique to MBB.