IUSB vs AGG: Holdings Overlap
IUSBiShares Core Universal USD Bond ETF
iShares · 17783 holdings · $43.2B · as of 2026-04-30
AGGiShares Core U.S. Aggregate Bond ETF
iShares · 13266 holdings · $137.7B · as of 2026-05-31
Holdings snapshots are 31 days apart (IUSB: 2026-04-30, AGG: 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 IUSB and AGG?
iShares Core Universal USD Bond ETF (IUSB, by iShares) holds 17783 positions; iShares Core U.S. Aggregate Bond ETF (AGG, by iShares) holds 13266. They have 11355 holdings in common, and by portfolio weight the two funds are 70.3% identical. In practical terms the pair is heavily overlapping, with largely the same stocks driving both funds.
- Overlap by Weight
- 70.3%Sum of the smaller weight of each shared holding
- Shared Holdings
- 11355IUSB holds 17783 · AGG holds 13266
- Weight in Shared Holdings
- IUSB 79%·AGG 90%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 IUSB
6428 of 17783 positions (20.0% of the fund) are not held by AGG. Showing the top 30 by weight.
- U.S. Treasury Notes0.26%
- U.S. Treasury Notes0.24%
- Uniform Mortgage-Backed Securities0.22%
- Government National Mortgage Association0.21%
- Uniform Mortgage-Backed Securities0.20%
- U.S. Treasury Notes0.19%
Only in AGG
1911 of 13266 positions (8.2% of the fund) are not held by IUSB. Showing the top 30 by weight.
- Uniform Mortgage-Backed Security, TBA0.20%
- Uniform Mortgage-Backed Security, TBA0.16%
- Ginnie Mae0.14%
- Uniform Mortgage-Backed Security, TBA0.14%
- Uniform Mortgage-Backed Security, TBA0.13%
- Ginnie Mae0.12%
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| IUSB | -0.2% | +0.3% | +2.8% | +4.7% | +0.2% | +1.8% | 4.28% |
| AGG | -0.3% | +0.0% | +2.4% | +4.2% | -0.2% | +1.4% | 4.04% |
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 IUSB vs AGG →
Shared Holdings(11355)
The top 10 shared positions account for 5% of the overlap, led by U.S. Treasury Notes, U.S. Treasury Notes and U.S. Treasury Notes.
| U.S. Treasury Notes | 0.37% | 0.41% | 0.37% |
|---|---|---|---|
| U.S. Treasury Notes | 0.37% | 0.38% | 0.37% |
| U.S. Treasury Notes | 0.37% | 0.41% | 0.37% |
| U.S. Treasury Notes | 0.37% | 0.40% | 0.37% |
| U.S. Treasury Notes | 0.36% | 0.39% | 0.36% |
| U.S. Treasury Notes | 0.36% | 0.39% | 0.36% |
| U.S. Treasury Notes | 0.36% | 0.42% | 0.36% |
| U.S. Treasury Notes | 0.35% | 0.40% | 0.35% |
| U.S. Treasury Notes | 0.34% | 0.39% | 0.34% |
| U.S. Treasury Notes | 0.33% | 0.39% | 0.33% |
| U.S. Treasury Notes | 0.33% | 0.35% | 0.33% |
| U.S. Treasury Notes | 0.32% | 0.31% | 0.31% |
| U.S. Treasury Notes | 0.29% | 0.37% | 0.29% |
| U.S. Treasury Notes | 0.33% | 0.29% | 0.29% |
| U.S. Treasury Notes | 0.29% | 0.31% | 0.29% |
| U.S. Treasury Notes | 0.28% | 0.33% | 0.28% |
| U.S. Treasury Notes | 0.34% | 0.28% | 0.28% |
| U.S. Treasury Notes | 0.27% | 0.27% | 0.27% |
| U.S. Treasury Notes | 0.27% | 0.31% | 0.27% |
| U.S. Treasury Notes | 0.28% | 0.26% | 0.26% |
| U.S. Treasury Notes | 0.26% | 0.30% | 0.26% |
| U.S. Treasury Notes | 0.26% | 0.33% | 0.26% |
| U.S. Treasury Notes | 0.26% | 0.32% | 0.26% |
| U.S. Treasury Notes | 0.25% | 0.31% | 0.25% |
| U.S. Treasury Notes | 0.25% | 0.29% | 0.25% |
Showing the top 250 of 11355 shared holdings by overlap weight.
Frequently Asked Questions
How much do IUSB and AGG overlap?
IUSB and AGG overlap by 70.3% of portfolio weight. They share 11355 holdings (IUSB holds 17783 positions and AGG holds 13266), based on each fund's latest SEC-reported holdings.
Is it redundant to own both IUSB and AGG?
The two portfolios are 70.3% identical by weight. Owning both mostly doubles down on the shared core rather than diversifying: the same large positions drive both funds.
What are the biggest shared holdings of IUSB and AGG?
The largest positions held by both funds are U.S. Treasury Notes, U.S. Treasury Notes, U.S. Treasury Notes, U.S. Treasury Notes and U.S. Treasury Notes. Together the top 10 shared positions account for 5% of the total overlap.
What does IUSB own that AGG doesn't?
6428 positions (20.0% of IUSB) are unique to IUSB, led by U.S. Treasury Notes, U.S. Treasury Notes and Uniform Mortgage-Backed Securities. In the other direction, 1911 positions (8.2% of AGG) are unique to AGG.