ISTB vs SCHZ: Holdings Overlap
ISTBiShares Core 1-5 Year USD Bond ETF
iShares · 7059 holdings · $5.1B · as of 2026-04-30
SCHZSchwab U.S. Aggregate Bond ETF
Schwab · 12081 holdings · $10.5B · as of 2026-03-31
Holdings snapshots are 30 days apart (ISTB: 2026-04-30, SCHZ: 2026-03-31). 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 ISTB and SCHZ?
iShares Core 1-5 Year USD Bond ETF (ISTB, by iShares) holds 7059 positions; Schwab U.S. Aggregate Bond ETF (SCHZ, by Schwab) holds 12081. They have 3258 holdings in common, and by portfolio weight the two funds are 31.8% identical. In practical terms the pair is moderately overlapping; they share a meaningful core, but each fund adds distinct exposure.
- Overlap by Weight
- 31.8%Sum of the smaller weight of each shared holding
- Shared Holdings
- 3258ISTB holds 7059 · SCHZ holds 12081
- Weight in Shared Holdings
- ISTB 74%·SCHZ 34%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 ISTB
3801 of 7059 positions (25.0% of the fund) are not held by SCHZ. Showing the top 30 by weight.
- U.S. Treasury Notes0.46%
- Freddie Mac Multifamily Structured Pass Through Certificates0.21%
- Uniform Mortgage-Backed Security, TBA0.20%
- Benchmark 2023-B38 Mortgage Trust0.15%
- Freddie Mac Pool0.13%
- Freddie Mac Pool0.12%
Only in SCHZ
8823 of 12081 positions (64.9% of the fund) are not held by ISTB. Showing the top 30 by weight.
- U.S. Treasury Notes0.44%
- U.S. Treasury Notes0.39%
- U.S. Treasury Notes0.38%
- U.S. Treasury Notes0.38%
- U.S. Treasury Notes0.38%
- U.S. Treasury Notes0.38%
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| ISTB | +0.3% | +1.0% | +3.0% | +5.0% | +1.9% | +2.3% | 4.27% |
| SCHZ | -0.2% | +0.1% | +2.5% | +4.2% | -0.2% | +1.4% | 4.20% |
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 ISTB vs SCHZ →
Shared Holdings(3258)
The top 10 shared positions account for 9% of the overlap, led by U.S. Treasury Notes, U.S. Treasury Notes and U.S. Treasury Notes.
| U.S. Treasury Notes | 0.34% | 0.36% | 0.34% |
|---|---|---|---|
| U.S. Treasury Notes | 0.89% | 0.31% | 0.31% |
| U.S. Treasury Notes | 0.99% | 0.31% | 0.31% |
| U.S. Treasury Notes | 0.46% | 0.28% | 0.28% |
| U.S. Treasury Notes | 0.67% | 0.27% | 0.27% |
| U.S. Treasury Notes | 0.96% | 0.27% | 0.27% |
| U.S. Treasury Notes | 0.98% | 0.26% | 0.26% |
| U.S. Treasury Notes | 0.26% | 0.26% | 0.26% |
| U.S. Treasury Notes | 0.86% | 0.24% | 0.24% |
| U.S. Treasury Notes | 0.24% | 0.26% | 0.24% |
| U.S. Treasury Notes | 0.73% | 0.24% | 0.24% |
| U.S. Treasury Notes | 0.32% | 0.23% | 0.23% |
| U.S. Treasury Notes | 0.71% | 0.23% | 0.23% |
| U.S. Treasury Notes | 0.91% | 0.23% | 0.23% |
| U.S. Treasury Notes | 0.80% | 0.23% | 0.23% |
| U.S. Treasury Notes | 0.56% | 0.23% | 0.23% |
| U.S. Treasury Notes | 0.70% | 0.22% | 0.22% |
| U.S. Treasury Notes | 0.55% | 0.22% | 0.22% |
| U.S. Treasury Notes | 0.59% | 0.22% | 0.22% |
| U.S. Treasury Notes | 0.22% | 0.26% | 0.22% |
| U.S. Treasury Notes | 0.32% | 0.22% | 0.22% |
| U.S. Treasury Notes | 0.64% | 0.22% | 0.22% |
| U.S. Treasury Notes | 0.25% | 0.22% | 0.22% |
| U.S. Treasury Notes | 0.60% | 0.21% | 0.21% |
| U.S. Treasury Notes | 0.53% | 0.21% | 0.21% |
Showing the top 250 of 3258 shared holdings by overlap weight.
Frequently Asked Questions
How much do ISTB and SCHZ overlap?
ISTB and SCHZ overlap by 31.8% of portfolio weight. They share 3258 holdings (ISTB holds 7059 positions and SCHZ holds 12081), based on each fund's latest SEC-reported holdings.
Is it redundant to own both ISTB and SCHZ?
The two portfolios are 31.8% identical by weight. Owning both is defensible: they share a meaningful core, but each fund adds exposure the other lacks.
What are the biggest shared holdings of ISTB and SCHZ?
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 9% of the total overlap.
What does ISTB own that SCHZ doesn't?
3801 positions (25.0% of ISTB) are unique to ISTB, led by U.S. Treasury Notes, Freddie Mac Multifamily Structured Pass Through Certificates and Uniform Mortgage-Backed Security, TBA. In the other direction, 8823 positions (64.9% of SCHZ) are unique to SCHZ.